I agree with most of it. But If both Saka and Foden the only two left footed right winger, we will have the same problem like the game vs France. Who to replace Saka in the 70mins? Even though Bowen and Rashford can play right, it is obviously not as good as Saka or Foden as RW.
Another problem is that we will not have a good right footed set piece taker on the pitch (if Walker starts over TAA and Tripper). And set piece is a very important part of England play. Additionally if Luke Shaw starts as LB, it will be even more weight on Rashford argument. Foden offers good crossing on the left but Shaw can as well. Rashford can provide cut in threat well neither of Foden or Shaw can.
From England perspective it makes more sense Foden or Saka for the RW. A bit competition is good.