Let's assume medium resources
If a civ such as romans builds a cc, then it has no resources for a barrack afterwards. For other civs such as gauls, barracks don't cost stone, so they are fine.
Can that be balanced, for example, a resource option 'Nomad'?
I think otherwise it is unfair if some civs don't have stone to build a barrack from the beginning, while others do can. Remember there are quite a few maps, very stone is not really equally distributed and only a few mines are available.
Also for more spicy games with a very low ceasefire time it is a huge advantage.
What are your thoughts on that?