I think they'll do fine, they really should have been called something like 'Generic Ancient Mediterranean Infantry', but Numidians does sound better. You have a lot of options on the sprues so you can make up javelin throwers, bowmen and slingers. They come with medium round shields, so if you can get hold of some Pelta shields, that might be good to mix in.
I've personally used them for Carthaginian spearmen, Jewish Revolt, some ECW Irish and Scots (with bits from Warlord and Perry Sprues) and have tried a few test models as Successor levy phalanx (just add 8cm wire spears). With larger shields they'll pass as Greek-esque hoplite militia (which is what I've done with my Carthaginians).
"Wyrd bið ful aræd"