I don't mind TAA in midfield in theory. International football is not a press heavy game and the team could really benefit from having that quality passer from deep. But if you're going to make that kind of move, the rest of the side needs to fit. You need runners in the front line (or else what's the point of having a deep lying player with such a quality passing range) and you need to have a tactic that involves dropping Trent into the backline in possession to get on the ball when facing the field. Germany pushes its two fullbacks forward, drops Kroos into a back three, and then he looks up and can use his passing range. England just played Trent like a bog standard midfielder, often receiving with his back to goal and in congested spaces, and that's just a recipe for disaster.
This is Southgate's problem in a nutshell. He has some ideas about how to tweak things, but is too much of a coward to actually follow through with the logical implications for the rest of the team.
Unfortunately, the options for truly changing the side are limited by Southgate's selections and his marginalization of White. By leaving out Rashford he has nobody to stretch the play, he somehow picked zero fit left backs so there is nobody to really provide width over there except maybe Gordon, and he has committed to an aging RB who can't invert or overlap effectively. Basically, he committed to getting nothing in attack out of both his fullbacks and to having a front line that almost exclusively wants the ball to feet. He can swap out TAA for Mainoo or Wharton but those limitations will still exist.
I think given those limitations the best idea would probably be Palmer and Bellingham as twin 8s and Gordon LW. Four stay at home defenders shielded by Rice, two wingers to provide width and stretch the play, then hope its enough of a platform for those central players to create some magic. If you struggle to progress the ball, push Bellingham and Kane close together and play long to them.