There are so many complainers asking for a panel to see your allies health/mana, and your enemies items. THIS SHOULD NOT BE IN THE GAME, THIS WILL MAKE IT EASY MODE.
Reason #1: This will eliminate the already small amount of communication between teammates in this game. I've played some games with my team on Vent, and very little needed to be said to dominate the other team, most of the time it was "I've low mana, or "watch out, X, this enemy is coming for you.", or "this enemy has low health". In games without vent, most of the things people type are similar to these. An example I use is if someone has a Sedna for a teammate, the Sedna player should have to take the couple of seconds to type out "i've low mana" to let them know they should not be expecting a Heal any time soon if they get damaged.
Reason #2: The game already has barely any micro-managing going on. If you're an assassin micro is practically non-existent. If you're a general, there are few times you need to: getting your minions to set off Reg's mines, getting your gunners to attack towers, and harassing someone with spirits. Beyond that there's almost nothing. If you look at pro RTS players, their mouse is constantly moving. They're monitoring everything they can: how close a certain building is to completion, how many units are still in a queue and things like that. People in this game should have to at least move their mouse over an ally to see their health, doesn't matter if they're in a cluster, you can just press CTRL to target only demigods.
Reason #3: This will make people lazier when they can just glance at the panel without bothering to type anything to let their teammates know they're at low mana, and eliminate the need of people looking at the item list to come up with their own strategies when they can just copy the items of someone who pwned them.
Reason #4: Compared to others, this game is very easy to master. Knowing is half the battle. Literally. If you have enough experience to know that the scaled helm is better than the plate visor, you're already at a considerable advantage over someone who might not, even if you have equal skill level, micro-skills, memory, reflex etc.. A panel will make it even easier, making it practically a joke.
Think of other games. I haven't played Warcraft 3 in a while, but as far as I remember, allied heroes were not shown in the side panel, if you had a Paladin with Holy Light or something, you had to mouse over allies to see their health/mana. If they died, you got a message but that was about it. Few games let you see your teammate's mana. In many FPS, you need to mouse over an ally to see their health too.