i totally agree to play every civ for its bonus and thats why i usually go fc and x-bow...
next question is, what you do with chinese? same position as brit...how to use its technology bonus best? i dont have a good strategy with archer civs on pocket (unless mayans ofc 11)...
The key with xbow pocket is to hit the other pocket. Its useless to chase knights around the map. Not recommending the xbow strategy, just telling my opinion. You have to let your flanks suffer for some time. Might work if both can wall up.