At the moment he's being asked to be the main defensive/holding midfielder but he doesn't have the positional sense to be good in that role and being asked to do it is taking away the things he was good at (although that is also partly explained by a lack of fitness with being out so long) . He was at his best best for us when playing alongside Hemdani. They complimented each other well, Thomson doing the ball chasing and adding the energy and Hemdani closing down space and intercepting passes.
Hopefully when Edu is fit again they will form a good partnership, one to sit and one to go and close the ball because McCulloch is never the answer for central midfield.