Probably too overpowered which seems to be why they might be cancelling one buff out for the other. Summoning is already super powerful as it stands
But actually my two-hand Warrior(with 80% critical chance) deal 1000+ damage (with almost-always critical hit) when my summoner's demon only hit 450+ every time.
Summoner is just a funny and balance choice for me when 2-H warrior could make much much more damage.