Typically managers coming in get to mould their own teams, not as drastically as in football where you can see wholesale changes within the space of a single window, but through natural attrition they can bring their own people in. Part of the interview process typically includes a couple of hours with the team, in some capacity, so both sides can make an educated guess as to whether it's a good fit.
The undertone of some of Acun's comments suggested, on at least a couple of signings, they went against LR's opinion on some signings (which is their prerogative) but were then pissed when he still didn't use those players.
If I was forced to work with certain people even if I didn't consider them the right people for the job, I'd be pretty pissed. If it turns out I was wrong, I'd have no qualms about falling on my sword (which is what LR ultimately did).