I believe it was quite accepted assumption that Rich can cover all 3 positions in frontline, wasn't it ?!?
He is right-footed, so he wouldn't play fully like inverted winger, but it does not mean right-footer cannot shoot from right wing.
Plus there is Moura who can play on the right if needed.
And in general depth of Kane, Son, Kulusevski, Richalidson, Moura and if needed Perisic feels quite sufficient. There has to be some flexibility and if injury crises hits, then tough luck but some players have to play in new positions.