Assassin doesn't work as anything. They should only be picked when someone wants to minimize their fun and chances of winning. (there are rare exceptions where perfect assassin equipment can be found and dodge can be made high enough)

I'm an aggressive player and prefer assassins and mages.   Warriors are acceptable.  I don't like defenders.

Assassins have high chances of getting a critical hit.

Mages can cast protective spells (like gift of iron and fire protection) and can cast aggressive spells (like sunder).  If your sovereign is a Beastlord, you also want him to be a mage to get high spell mastery.

How are defenders doing right now actually relative to warrior? I've been using those 2 classes very heavily and always making my sovereign a mage.

Usually I find later in the game, plate wearing classes tend to be outfitted in full champion's plate gear, equipment wise, and whatever good weapons have been salvaged/looted from quests/dragons/other beasts.

Hmm, there is a particular assassin build though that can solo the entire map.. Granted, it needs a custom faction to work, but it can solo everything and anything 100%

For faction, you need wraiths, with lucky, scout(optional, but REALLY helps with leveling up faster), and any disadvantage other than magic vulnerability.

Then your Sov gets brilliant, the 2 abilities that give accuracy and spell resistance per level, and this is critical: air magic disciple. You want tutelage readily available from the get go, as well as evade. For disadvantage I pick scarred, as I rely on wraith touch to be in top health most of the times.

When you start, use tutelage and evade on your sov, pick potential first, then on leveling focus on dodge first. Also research monk robes asap, you NEED those. By the time you get the +1 dodge per level trait, it is possible that you have found another +dodge item, use it even if it is the weakest competitor for it's slot. Eventually you will lose your militia and spearmen, and by then you need your dodge to be above 80. Next stop is the +10 dodge cloak. By that time, it will be quite impossible to get hit in battle.

After you are done with +dodge, go up vital strike, and grab the eviscerate skill, then finish vital strike and go up the armour piercing skills.

As far as weapons go, anything with armour piercing or +crit chance and damage is a go, although eventually you will get the druss blade which is awesome for your character. Generally you want to stick with swords/daggers and shields for the extra dodge, initiative, and counter (counters crit too, and with such a good dodge and being solo, countering is often half your damage right there.) Note that +resistance items and elemental defences are also highly sought after.

The magic skill you search for in your champions you recruit is earth. You want nature's cloak on your sov asap, to be able to tackle an arena (and for general drake and such monsters in lairs)

The end product is huge amounts of stacked evade (my last assassing sov had 130+ evade, but that doesn't mean he doesn't occasionally get hit, only that he can heal that minor damage back up with wraith touch), often a 50% crit chance with much boosted crit damage, and a killing machine that ignores armour and never gets hit. I used that Sov to solo the entire map, taking everything and everyone, from the highest level dragons, to all wildland bosses.

He usually 2-3 hits ashwake and chambercoil dragons.

The key is to know what you can tackle at each step of the build-up, and get xp fast.

Does this make assassins op? Well, this assassin is op, but I doubt this applies to anything else but this very specific build. I will try a krax blood or tarth blood assassin now that I perfected this one, but I doubt it is going to work without wraith touch and the inherent dodge bonus wraiths have.

The dragon's breath will still kill you though, unless you have 100% fire resistance.

The only problem with that build is swarm. If you get Tectonic Bulwark (immune to swarm), assassin builds can be quite insane. 

Its a straight up comparison.

So if i have 80 accuracy vs 20 dodge, i have a 60% chance to hit. 140 accuracy would negate 40 dodge.

warriors deal more damage than assassins with most weapons, including the assassin's added chance for crits.

If you think assassins are fun, thats one thing. If you think they are in good shape as is you are either playing on low difficulty, or skewing your champions level by having dense monsters or higher world difficulty(which actually lowers the game difficulty by providing extra experience for your champions).

To me the main issue is that warriors seem better at the assassination role than assassins. If you want to make an assassin warrior, get a big club with all of the attack bonuses and then the crushing blow bonus tree, and you now have a guy that can rack up massive damage in a single hit, enough to one shot many creatures.

At first I favored warriors but now I have to say I like the assassin a bit better.   You can make them extremely powerful with a build like MoRmeNgIl's, but even without that I think they hold their own.  They just have more "spikey" damage due to crits compared to a warrior's more consistent damage.  Furthermore, defense-penetration scales well late-game.  Their damage mitigation mechanic (dodge) is also "spikey" in nature, but you can raise dodge to truly ridiculous levels and take NO damage from many, many attacks.  Anyway, ultimately it comes down to personal preference.  I've enjoyed having a warrior and an assassin in the same army.  Assassins also have more mobility, with more initiative talents and the "Switch Places" ability (whatever it's called), which is pretty sweet against a bunch of ranged opponents.

The thing I dislike most about warriors is that you are encouraged to specialize in a certain weapon type without knowing what weapons might drop for you.  Cleave is too situational, and bash is just *yawn* after awhile, especially considering it's an easy one to spam with all your regular troops.  Also, club-type weapons have the worst initiative of any melee weapon, and the more I play, the more I favor high initiative.  For this reason I usually end up going the sword spec route, because a) a lot of the nice drops from quests and/or wildlands bosses are swords and the last upgrade gives you a counterattack with any weapon.

Just go get a Heartseeker from the Epic Arena quest and give it to your crit-build assassin.  If you have Masterwork Chain you can even buy him some pretty good armor to go with the excellent dodge.  You won't be sad.

Re: defenders, they just haven't caught my attention yet.  There's no true "tanking" mechanic (i.e. taunt or the like) in this game, and generally I just like to kill stuff fast, hopefully before they even get an action in.  If enemies are getting even remotely close to my back line, something has gone terribly wrong.

Edit: LOL at the forum inserting a smiley face for my b-parenthesis.

That may well work but it sounds painfully boring

what's the point to take assie or warrie if they weaker than mage anyway? mage get useful magic. deal more damage. etc. assassin or warrior can tank? nope. deal? nope. more magic? nope. worse than even general. only useful skill in assassin is break. dark mage take aoe break. can tank(aggro) with summon. damage. useful spells. more exp to get high lvl.

i'm playing ridiculous and game is ridiculously easy when i use mage + defender(henchman). use invincible. use wail or thunderbolt. = win. my army score is normal ~ strong but this easily beat epic quest etc.