Well, thank you for your kind words.
Niceties aside, historically elite units were not any smaller than line ones of similar size, rather it was often the opposite as rulers took all care in maintaining their "prestige" units.
What limited their unit was economical or political considerations rather than some inherent superhuman quality of the elites themselves.
In XC we went for a more sober representation of elites than XGM, meaning that while being extremely effective units on their own they will perform poorly if not used in their intended role.
What limits their number (especially in the later builds) is their cost within the rebalanced economy.
This means that before you can afford high quality armies you will need to build your economy to support them, and even a well developed empire won't be able to keep around an "all elite" stack without that crippling their purse unless they have huge cash reserves in store.
Finally, XC is not just "XGM plus", it's a complete overhaul that is made for more strategically oriented players and ones that likes battles decided by smart tactics, so if you play it don't expect to use the same mindset as in XGM or you will fare poorly.