Wimp.

The only instance where it's actually a problem is wall battles, or in any case I've been unable to get the buggers to switch to swords there. Otherwise it just requires some micromanaging (namely, occasionally "reissuing" the attack order so they swap weapons back to whatever is desired) to deal with. Not a big deal with the likes of the Hypas and other elites, which shoudn't be present in very large numbers anyway, but I'd imagine it could be a bit of a hassle with, say, large numbers of Massilian hoplites.