I think it's very important to consider each players role too.
Andre Gomes is playing so deep, almost like a defensive midfielder which is a position he's never played in before. He was at his best for us when dictating play, spraying balls and driving forward with it at his feet. I don't know if it's a tactical decision from Ancelotti to have him here or if his legs have gone.
Sigurdsson, again, isn't a CM or a LM. He's a number 10 and we got the best out of him when playing there last season when he was arguably one of our better players. He's never played in a two in the middle of the pitch - I know this doesn't excuse his heartless performances, but still.
It seems like there's a bit of an identity crisis at the moment, I recognise that DCL plays better in 4-4-2 with support but that really doesn't suit the team elsewhere going forward. There's no creativity and we don't have the wide players (aside from maybe Walcott) who can run at a defender and get a ball into the cross. Even Digne has struggled getting forward with the 442.
Damage limitation until the Summer, finish as high as possible and build a proper formation/team. We need 2x CM and a Winger or two in my opinion and they should be priority above every other position.