If you're limited to one summon then I don't think necromancer is worth a damn.
Absolutely correct. But if they do that to the Necromancer, then it's not a Necromancer. It's their 6th level ability that makes them one, and that ability is multiple summons. Their 3rd level ability is very weak. Multiple summons is the whole point of a Necromancer, it's all they really got. If they stick to 1 summons even with subclass abilities, I'll have to wait for someone to mod a correction.