The tactics have changed this season. Its not all down to personal but some of it is affected by this.
The pivot role appears to have gone completely. I'd suggest this is linked to not having a full back in the same vein as Maatsen. Last season saw the left back step out with the other full back or pivot player tucking in. Its not something that's happening currently and is leaving Cullen without a real role.
Stepping out from the back. I think I've seen Beyer do it once this season. Last season the defenders stepping out and past the striker often beat the press early and enabled us that extra space to play. I'm not sure if its confidence or ability but neither centre half look interested in progressing with the ball.
Wide player. Wingers look isolated completely. Fosters doing a decent job as a lone striker but isn't the same hold up type striker as Barnes was. We seem happy to give the ball to the wide men and say beat 3 men and run at goal. We are asking a lot of kids like Odebert and Koleosho. Overlapping runs have been poor and when we have beaten men and made it into the box there's only Foster to aim for. Last season the likes of Zaroury and Tella were both making runs arriving at the back post from out wide.
We seem stuck between last years system and deploying a new system.
Personally we either need to can what we are trying and revert to a more tested formula from last season. Or ditch last years tactics and set up as a counter attacking unit. Currently we are trying to do both.