It really depends of context and situation but usually its on managers, put aside about him bringing/selling players at the end of the day he has final call when it comes to current squad.
In RR case, if all shit is true, seniors cant be bothered because he is interim, they aint hungry, willing to run and so on, he is/was in position to just give chances to young ready or not players and mixed them with some seniors that might have his back, both groups wount achieve a goal but at least you would maybe see some fight. Otherwise, just w8 summer and new manager might come out and say how everyone gets a clean slate to prove them self and we will watch majority of those pricks for another season. Damn, Ole really did a number on us for last 3 years.