AH is 4 turns away from Italy, in an Italy first strategy usually your round 1 stuff is what goes to it then you just get fighters for the main battle and infantry to keep russia away.
If you get naval it is stupid because it only puts 2 infantry 1 turn closer to Rome for each transport. Since you are taking it on round 5 usually like it is better to just send more of your round 1 units in that direction.
You attack at round 5 if you lose you lose the game simple as that, that is how all ins work. So send enough to take it and buy fighters as necessary.
So between 5 territories that make it for a round 5 attack on rome, you pick out whatever you feel is enough to take rome and you move the units in that direct. Add fighters to gain air superiority later. You can advance 1 infatry on round 2 in that direction to be with your fighters 2 space away.
As long as you plan proper it is not hard. Transports do not improve things. Maybe if I can get rome a whole round quicker it would be worth the investment. Can you take Rome on round 4 with naval purchases?