the rules ensure that the TTs cant really do double duty that way (you can use them twice but its not faster) though it is fun to imagine bringing along an extra transport during the US cross to load up those brave, brave, no-combined arms Frenchies from North Africa. Or brits. The rules just make it too choppy to implement very well.
A much better exploit is
flying into the attack with fighters u moved 4
landing them planes on an allied carrier, then it moves 3
then it gets attacked, you help defend, it blows up, you move 1 more
you moved 8 spaces with a fighter and fought twice in 1 turn lol