The local mics probably have nothing if anything at all to offer in your homeland provinces. I haven't played Lusotannan yet, but I guess there won't be much in the Iberian peninsula. You'll get heavier units at higher-level factional mics, but don't expect very many of them. The Lusitanians were adept at skirmisher/ambush stuff and their light infantry is excellent at it.

Iberian units you can train on the east coast in your factional mics. Check this thread for some handy stuff.