So what do I use the Gargoyles of Barda and the Birdmen of Catrazza as?
Paper weights.
But seriously folks, even "obsolete" units usually can be used as a cool "counts as" other infantry types. If they still look good and already have a nice paint job I'd find an in-game use for them. Swordsmen, spear men, bowmen, flying units, etc., I'm pretty certain those are still usable in Warhammer.