Look, with regards to Unsworth, it may well have been a case of being promoted out of harm's way.
Maybe he's a bang-average coach. Maybe he's not very good at coaching or managing but if you are a recently retired player and want to stay in football - the fuck else you gonna do?
We've possibly all had decent line managers who don't know shit about our jobs but are still good at theirs. With no DoF in place when he started, if Unsworth is ambitious he'd have thought "Hang on - I can be my own boss here and in a few years I won't be putting out the cones for a bunch of kids." He'd have been banging on Bill's door with ideas to take the academy forward and what they need and what they would like.
I wouldn't be surprised if Brands has come in - looked at Unsworth's skillset, as well as his performance, and decided that this was a better fit for him. Sure he could have gone for an outside hire, but if you have a decent fit, who's been at the club for years and bleeds Blue.... why would you go anywhere else?