Yep, i think the path of the commander is overpowered and boring, because as soon as a commander is in an army the unit stats are unbalanced and the commander is not even using an active ability.

The commander bonuses should be active abilities with a duration of 1 turn and a cooldown of 3 turns. During one turn the commander could increase the accuracy of the army by 25 and during another turn he could increase the spell resistance of the army by 25, ...

i disagree with the "overpowered" part. the bonus accuracy is great for early game troops, since they likely won't have all the accuracy boosts from fortress training buildings, but mid/late game troops start at rather high accuracy anyway when built in fortresses, so most of the commander bonus is wasted at that point, unless you fight stuff that has a high amount of dodge. command is a great ability, but on the other hand, if that commander were a warrior, assassin or evoker mage he would kill a few enemy units himself instead of using his minions. don't think that's overpowered - that's the commander's way of participating in the fight.

but i agree that the tree could be a bit shorter. 4 traits in a row that all do the same thing seems too much. removing one of the accuracy traits might do the trick here. maybe also add one more active ability branching off somewhere in the tree to give him something to do while command is on cooldown. 

Mages and Commanders are both viable and strong hero types.

I think the others ones are a tiny bit weak right now.

Instead of taking commander to get a big boost to accuracy you can make a custom race and choose lucky. It is +25% accuracy and +25% dodge for you and all your troops. A crazy powerful ability.

Yeah, lucky should cost 2 points or should be changed to give the attacker a second attack roll like backswing.