I think the 5-4-1 was really mean to be a 3-4-3. Townsend said as much in his post-match interview.
Issue was, we had no way of making the ball stick up top so every time we went long it just came back to us. Townsend specifically mentioned Chelsea, who play with 2 10s both capable of dropping deep to get on the ball.
We've seemed to play this shape in the two games so far when the onus has been on us to control possession and in both games tbh we've failed at it. Not to say it can't work, but it needs a player in there to get on the ball. I reckon that could be James' role in that system, as one of the three. If the other two are one of Richarlison/Gray/DCL, then it's a good front three and can be amended as and when. While DCL is out, if Rich is starting up top we can't be just lumping things up to him. Defensively also leaves us with plenty of cover meaning Doucoure can join in the attack. We have to be playing him in behind and that means throughballs or passes into the channels. It's not gonna happen every game and right now James doesn't get in our 'first team' based on how we want to play, I think most people accept that.
We haven't really played 4-2-3-1 btw. If you look at the avg positions in those matches it was pretty much 4-4-2/4-4-1-1. I don't think James works in those systems. If we played 4-2-3-1 with Gray/Richarlison either side it could work but do think he tends to get a bit bogged down when starting central.