Quite like Gundogan as a player but him coming into the team does seem to have had a detrimental effect in some regards. When Fern was on his tod it was working perfectly with him dropping into the middle as the centre halves split and the full backs came in-field. It made the pitch appear massive with loads of space all over the shop. Both Silva & De Bruyne were also playing brilliantly when deeper. Having an extra body in the field makes the pitch suddenly appear cluttered.
Given the players we have I also don't think three at the back works for us. Our back four was basically a back two + Fern at the start of the season. A back three negates the need for Fern to drop so again leaves less space in the mid, which is especially exacerbated if Gundogen starts in there as well.
A back three works well with attacking wing-backs coming from deep, our back three has wide men who are too far forward too soon.
Go back to a back four / two, let Fern drop in, bring back Silva & De Bruyne, and Robert's your proverbial uncle