They might not, but they hardly need to. A 14th-level necromancer who encounters a single powerful undead is likely to try out Command Undead as a matter of course, unless they've already got a powerful lackey.And how is a party coming up against one for the first time going to know that?
Probably not a lot. So? I didn't say it was going to happen often, just that when it did happen, it would be like Christmas come early.How many people play necromancers?