People always say this about the one holding mid with two 8s pushing ahead but it’s worked numerous times.
City played the whole of 18/19 with Fernandinho sitting and the two Silvas ahead of him, talk about lightweight.
Real Madrid unlocked their best period of dominance when Casemiro went to the sole sitter and had Kroos and Modric ahead. Same with Busquets sitting deep and Xavi Iniesta ahead.
Even Everton did well in the past in Moyes first spell with Carsley deep and Cahill Gravesen pushing on. Mourinho also made it work with much more physical players admittedly.
It all just hinges on whether Moyes sees KDH as a player that can play deeper or whether he has to play number 10.
One thing that is for certain though is that playing 4231 with a specific number 10 is a formation that can get quickly found out and requires two very good deep lying midfielders which I’m not sure we have with Gueye in the team.