Like I said earlier I have looked into transporting troops from east coast to west/central Africa. I have never really tried it because I think the consequences will be too big elsewhere. Once the shuttle is established you need 6 transports and this will allow you to put 2 fast movers and 2 infantries to French equatorial Africa each round: You need two transports in 89, 3 transports in 87 and 1 transport in 82. You build 2 inf and 2 fast movers in central USA each round and move to Mexico area bordering sz 89. Then you have 4 transports (2x2) shuttling 89/87 and 2 transports (1x1) shuttling 87/82 with the 2 infantries. Of course you have some starting units you can start with, but once you buy 2 infantries and 2 fast movers it takes 5 rounds for the fast movers to get to Egypt and 6 rounds for the infantries. This is the main reason why I have never tried, because it takes for ever.
But you also need more stuff: You need to control Gibraltar with a three-fighter scramble with at least a destroyer in 92 or 91, probably both. This will prevent axis sub from 93 to kill 87. Likewise, you need to control Morrocco and Algeria. Bombers from W-Germany or southern France can land here after killing 87. Or if axis control Algeria you have the same problem. Finally, you need to control the Atlantic Ocean so there are no enemy subs. In summary you need some navy and some planes.
So, what does this achieve, at best little, I think. Yes, you will get a nice number of American units to Egypt/middle east, easily 20 American land units by round 9 or 10. Like pointed out it’s possible to combine with Middle Earth and this will provide an allied fortress in the middle east. So, it can be a way to secure Cairo from axis take over and then prevent the win
Most likely there will be no pressure on Germany on the western front, and this will mean Russia is captured at the latest on G8. You also need to look out for a late sea lion. Finally, the question becomes if USA has enough resources to contain Japan. I don’t know.