I truly believe McVay tries to elevate the careers of his assistants. Find me an interview where he doesn't praise his assistants by name.
Now, he might have had philosophical differences with men like Bones, Phillips, and Kromer but he handled it all with respect and I doubt you will ever hear criticism of them from McVay. It surprises me when people assume dysfunction as a cause for departures. Perhaps these people were traumatized by Martz and Linehan?
A strong leader like McVay will never completely relinquish his role of setting standards and overall direction. Differences are inevitable. Will some people not really enjoy working with Sean? Sure, that's likely. But I've seen no indication that such a feeling is prevalent. But hey, negative imaginations always get the most press and speculation.
Personally, I've never seen a coach generate this many promotions so early in his career. This should be celebrated, not vilified.