Good advice indeed. However there are ways to actually take on the Rook in his farm.

The most important thing to realise is that going after Rook in his farm is not going to work.  Too much firepower and anything other then a concentrated team effort is not going to do it. However almost every demigod has a way to deal with this tactic.

You need to take down the farm. Whether you do this by outranging the towers (regulus) or AoE'ing them/stunning them (Torch) or simply do too much damage to them (UB's spit) for rook to keep up with, you can take them down. 1 or 2 towers is not dangerous. 6-8 are. Fortunately they can be destroyed fairly easily and do not regenerate. Needless to say the best time to do this is while he is tryingt to build the farm. It takes less time to destroy a tower then it does for Rooks tower power to cooldown. Add in that mana limits your tower placements and having them destroyed will dry you up very quickly (unless its late game and the mana regen is through the roof, then your just playing on the cooldown).

You can also keep a Rook from advancing very easily. Most rooks will make a farm and then move slightly ahead to build a new farm or a single tower to use as a launch point. If you are there waiting, taking down the towers as he puts them down, he will have an impossible time advancing. More importantly if you can do this to him at a point where his tower farm will be outside of where the waves are clashing, he wont be getting experience and gold as well.

Ive seen people use these tactics against Rook and ive had them used on me when I play Rook. It is VERY frustrating for the Rook player.

One last note, if you see an unatended tower farm. Spend the time to take it down, its worthwhile. It will take Rook another minute or two of standing in one place placing towers to get it back up (or much longer if you are harassing him and the towers while he does it).

tower damage is mitigated by Armor, meaning that Rook's "Tower of the Power" ability might be the only activated ability in the game that is affected by Armor. 

Rook's shoulder turret damage is also affected by armor. 

if you're playing a melee type DG that has to stand in the tower forest to attack rook (Beast, Sedna, Oak) then you'll benefit greatly (against Rook anyway) from emphasizing your armor stat in equipment choices. 

hit rook while hes setting up. Regulus mine ability is set off by towers, combine that with him outranging the towers makes regulus a pretty nasty counter to tower rook. In pantheon thats another story...

A single player can generally harass rook enough to slow his tower crawl down ALOT, or stop it earlier in the game. Once hes set up he makes for a invaluable safe haven for allied heroes, and if he sets up in your terriory getting him out is TOUGH.

Do NOT ignore rook! Ever!

I was just DOMINATED in a tournament game.  I got paired with an Erebus and I was QoT, we both generally knew what we were doing.  Guess who we got paired up against?  2 rooks on the 2 vs 2 map. (starts with a c, has only one path to the enemy base)  We both thought of the bright idea to port out straight away and cap the flags fast, by time we got back to start killing the first wave of minions we found that our opponents were rooks and they already had 4 towers up.  As they placed them in such a way to limit our ability to run past them to re-cap our flags while defending the only path to their base, basically all we could do was sort of sit there and watch ourselves get slaughered. 

I'm really starting to hate rook's towers.   

Well, by time we got to attacking rooks we'd both die.  I'm not saying we sucked but there were far too many towers and pounding rook/using reinforcements didn't really help.  It was a bad matchup since Erebus and QoT have a hard time, (at least QoT does in the beginning of the game) against all those towers on a small map.  If we tried letting the reinforcements soak damage to try and gank a rook we'd get chain boulder rolled and die.    Oh well, it happens, and I doubt we'll be seeing two rooks on the same map in tourny again with the same matchup. 

You forgot TB annhilating all of it while the towers are frozen doing nothing

When I play Rook I'm more concerned about Rain of Ice because with Circle of Fire they have to get close enough to get several towers in the circle, making themselves vulnerable to Boulder Roll.

A good Rook is mobile, even without his forest of Towers. The basis for your guide is sound, assuming that the Rook capping key flags, his team mates are retarded, and you've an organized group.

Some Demigod's can win 2v1 scenarios. Some Demigod combos can do great against 3v2. Below is a copypasta of my miniguide to stop a Tower Rook. It provides scenarios for different time frames occasions, not just one locked down attempt.

Mini Guide. How to stop the Towering Rook:

Minions. Most Generals have access to Minions. Some of those Minions are designed for Seige. Use them as they were meant to. Have them swarm the Towers while you focus on the Demigod.

Catapults. QQ.

Trebuchets. Yes, they target Rook Towers and take them down pretty quick.

Mana draining, cool down increasing abilities. The basis of a Towering Rook is mana. Remove that option.

Harassment. Early game, harasst he Rook. Don't let him creep, flag, or destroy buildings.  The Rook heavily relies on creeping/flagging for XP. If you let him get powerful, you lose all right to complain.

Focus Fire. If you have multiple heroes and you target all of your attention on towers, one at a time, they will be gone before he can overwhelm you.

Torch Bearer AOE freeze effect, very good on Towers.

Regulus... That's it, just this annoying prick.

Location. A smart Rook chooses a location on the map to buckle down. Play smart, force the Rook to move from that spot into another area. Don't let Rook setup a trap for you. Don't let the Rook push you. When you play into your enemies game, they will always have an advantage. It's one of the key foundations of Sun Tsu' Art of War, and it applies aptly to STRATEGY based games.

The Rook is not over powered nor underpowered. He is the ONLY SUPPORT ASSASSIN Demigod. His Towers exist, even after death as they are meant for a support role for yourself and your fellow Demigods. In terms of 1v1 with other Demigod classes, the Rook is one of the worst Demigod killer, even when compared to some of the Generals. His strengths, much like his origin, lay within' defense. Taking an area and holding it, slowly but surely pushing forward.

Regulus with range upgrade can attack the towers down.

Fire TB absolutely obliterates towers.  When the wave of creeps moves in, go in with them and drop a ring of fire in the middle of the towers.  You will fry bunch at a time.  Then back up and wand the little bit of health they have left.  If you keep killing his creep waves with ring of fire he can't really push your tower to structural transfer either.  So he is stuck playing back and being attritioned out by your fireballs.

Best tactic against tower rook is to kill Rook himself.

I occasionally play a decent trook as well and to keep fueled for towers, transfer and one attack skill, we tend to stack up on helmets. We need a good mana supply to keep rebuilding towers.

That means we have less armor and health than an assassin rook would have.

If you spec for high health, damage and armor, then you should be able to kill rook even inside his farm. I'm not saying it's easy, but even trooks have more than just one disadvantage.

After taking care of rook, take care of the farm.

Towering is really only good in the early game. It takes 16 seconds to throw up 2 towers at lvl 1, and that will be sufficient to deter any lvl 1 demigod. At lvl 10, it takes anywhere between 64-80 seconds to throw up 8 towers. The Rook has to throw up more towers at later levels to sufficiently deter enemy DGs, and this take more time.

Plus, DGs keep getting stronger, but Rook towers don't get more powerful after level 10. Catapultasaurii can outrange towers, which means that the Rook will have to run outside of his protective fortress to kill them. As mentioned before, trebuchets can easily take towers out.

At level 20, towers pose very little threat to enemy DGs. A Rook will have spent four points in a skill that is useless in the endgame. Rooks have to switch strategies at the endgame in order to still be a viable threat to the other team. The Rook's only advantage when using towers is fast farming that allows him to level up faster, and block lanes in the early game.

As an UB, I go try to keep spitting on Rook as much as possible, getting mana hats to keep up the spam. He'll use transfer to try to counter, but it has a horrible cooldown and eats up his defense, in which case, you come out winning as he retreats and you can wail on the forest and force him back. Putrid Flow is like the absolute comeback skill against tower rooks, sadly, it's lv15 and by that time, he's pushing the portals.

When I play Rook I just counter this by lining my towers as a wall so when UB gets close to spit he gets jolted by at least 4 towers at a time.