Throw in Keane as well tbh. The biggest problem for us last season was the amount of players we had signed. It´s so rare for any side to transform their playing squad and hit the ground running.
I think you are probably right.
Koeman was like a child in a sweet shop and could not stop spending. It was just too big a task to get all of those players to settle all at once. Of course, not signing a recognised striker was the worst mistake of all.
Silva may have been helped this season by the injuries to some of the players he signed. Bernard, Gomes and Minna were allowed to settle for a number of weeks at the club before playing. Each then came into a team that had settled to some degree with really only Zouma and Richarlison playing from the start and Digne after a few games.