It's much harder to teach an old dog new tricks. But if a manager picks based on potential and endeavour, can often resolve problems, by bringing in young players. It reminds the older players what its about, about not having the fear, about working incredibly hard, then talent shines through.
Most of the coaches we're looking at, had arguably most impressive performance when they were promoted from youth team and put youngsters in. But they knew club and setup intimately, showed faith in players from youth team.
Look at Guardiola at his clubs, he's put in youngsters willing to learn and put everything in for him and culled the older players who resist or challenge his authority.
Part of the problem, is that older players respect reputations and don't listen to ones they doubt. If Unsworth had maximum respect of fans, I think the new signings and bigger names would soon get in line or be dropped. But there has been lack of faith and plenty of fear of inexperience. But his young players have worked socks off for him.