I'd have to see that to believe it regarding the Bone Necromancer. Is your guy decked out completely or something because I've never heard or seen anyway take that build all the way.
Regarding adding more summons, the intention was more to give a Poison Necromancer in particular another golem in case one of the Fire Golems goes down. Other than that, you're right. It won't make that much of a difference. The skeletons are actually pretty handy at low levels.