The main issue you will run into trying to play a fullback on the side of their weaker foot is they are predominantly reliant on their strong foot to block crosses and shuttle, also they are on their weaker foot if they should choose to bomb up and stick a cross in from the left. However, Spence has clearly shown his defensive acumen on that left side with defending on the weaker foot being little impediment, not to mention the amount of wide players that look to cut in and will open themselves up to being defended on the stronger foot of an inverted wingback, and if our plan is predominantly to play Johnson on the left as an inside forward pending a proper replacement, and Kudus is providing width down the right along with the opportunity for an overlap with Porro who is also a proficient crosser, it makes sense to play a right footer on the left side who can invert to provide support in midfield allowing for an 8 to get up the pitch.
In this sense Spence is more useful as a LB than an RB for us, so I would probably agree with your assessment that we aren't especially desperate for one. I do think Udogie is going to take several steps up under Frank, similar to what we are seeing with Sarr atm though. Anyone's guess who ends up first choice there.
Would like to see RB cover for Porro come in however, he was one of our players who noticeably dropped off last season when his match load ramped up, and running him into the ground for a 3rd season in a row is asking for muscular injuries and fatigue to set in by November. If we're letting Biss go to Galatasaray then Gray needs to just be covering Palhinha, not him and Porro, he can't be used to cover the defensive line again this season or we risk losing sight of what he actually is in his development.
