The true heirs to the baronies will be grateful that they are restored to them and therefore be loyal to the King.
You honestly believe that? All self-respecting vassals plot in secret against their liege in the hopes that they themselves may one day rule in their place. You'd know that if you knew the first thing about how feudalism actually works.
And again, why would the king do that when, once in power, there'd be nothing to stop him from just keeping it all to himself? More importantly, why are you so desperately grasping at straws just to avoid doing the necessary work to further your own pet cause? I assure you, the only one who gives a shit is you. I guarantee you, nobody is going to do it for you.