FormerlyHemlock
Hero
We play totally different games.
I know. I think the same thing every time you post about how you have 6-8 combats every game night. My players, on the other hand, sometimes spend half the session sneaking around and the other half running against each other for political office, trying to get various NPCs to vote for them over the other PCs. We play very different games.
But note that I'm also talking about someone else's game here, not mine--the OP has expressed a desire to have hundreds of skeletons at a time, and as you can see I've extrapolated from lesser numbers of skeletons. ("Normally... but if there are 100 then you probably can't...") At my table, I've never seen a Necromancer with more than two dozen, and the player eventually got bored with smashing everything to tiny bits and put the Necromancer on the back burner in favor of another PC.
Presumably I don't need to spell that out explicitly but I find that with some people it helps, to avoid miscommunication, to say that explicitly. The hypothetical situation you just asked for advice on is being answered based on my extrapolating from similar-but-not-identical experiences. Also, drawing upon my experience as a DM running large battles with tons of monsters, which is basically a Necromancer has to do.