What is fascinating is originally the Summoner class was called the "Master Summoner" class.
It wasn't ABOUT summons at all, in fact there were no implications that it would even summon. What it WAS about, however, was manipulating summons and using them in new masterful ways. You could move your summons around, explode them for damage. An amazing assisting skill tree. There is SOME of that still in the game.
Heck even more so there was some implication that you could do things with ANY summon and create slight variations of summons.
The issue that mostly comes up is how monolithic summoning is. It is the only skill where you get far more than 10% effectiveness.
THAT and it in many ways kind of neutered the other magic trees because it begs the point use.
As silly as it sounds... I think the summoning tree would have been better off without a summon except maybe reworked totems and satellites... and instead have it assist OTHER summons.
Sure it wouldn't have been a solo skill tree... But I fell inlove with the "Master Summoner" concept and the game needs a coat of strategy.