can wonders allow specific unit recruitment?

hmmm i was just wondering if anyone knows the hardcoded limits on the effects that wonders have. If one could set certain unit types to require specific, then one could mod a wonder's faction-wide effects to simulate the movement of people and culture from one region to another as opposed to the zone of recruitment method. Then, factions like the seleucids (and the ptolemaics present in many mods) would require greek lands to recruit greek soldiers but could recruit them in multiple settlements. after all, any conquering people tends to settle in the land it conquers. Perhaps if combined with ZOR this could create a more elaborate recruitment system