It seems that there are players on each side of the fence regarding fleet commonality. How about simply creating a game world where fleet commonality either: doesn't apply, or is not as harsh as it currently is. That way its a win/win. If you want the challenge of fleet commonality, play a game world where it is included. If you want to be able to run various fleets, choose the option where it isn't included.
After playing for 5+ years on this account and my previous account, I would love the chance to operate multiple fleet types without, or with less of, a penalty.
Just my 7cents...