The changes do in my opinion cause more problems at the back. The relationship between the LCB and the LB for example. If both positions are being rotated all the time they don't develop the sort of automatic positional understanding of say VVD and Robertson for example. It also involves the DM too. Last year that was Dinho and he knew where Zinchenko and Laporte would be in relation to him. Recently we have had 3 different LBs, 2 different DMs and sometimes played 2 deeper lying midfielders. The permutations are numerous and despite the players intelligence I believe this can lead to errors.