I guess BA
will be the best airline to fit at FLL
as the only international carrier to fly to that airport due to that passengers flying from FLL
to London, have a much better advantage to get to their final destination. You can connect through LHR
and fly almost to any city you wanted to non-stop though there would be some you will need to make a stop before getting there. Anoher thing is that BA
is the largest international airline.