I think the bigger test for Sherwood is what he does through the summer, he has no experience in the transfer market what so ever.
He's shown himself to be a pretty good motivator even though he's some what simplistic with his tactics, generally get it forward as quickly as possible and make sure you get as players in and around as possible for when the ball arives. It works to a point if you've got enough firepower to score a few, he had that at Spurs and he's got reasonable attackins options at Villa too for where they are, they'll certainly do a lot better with that approach than the very restrictive game they'd ended up playing under Lambert. It'll never get them very far against the better sides though.
I can't see the full season/half season thing making too much difference to his approach or the effectiveness of it, unless they hit a particularly bad patch where he might need to try something different to get them out of a rut, I think he'd struggle to change things in that situation as he's just too one dimensional but then plenty of managers seem to go that way.
As said I think the summer will be potentially difficult for him, does he know what positions he needs to strengthen or what sort of players he needs to improve the team? He's shown he's got a decent eye for a young player and isn't afraid to give them a chance but has he got a good enough eye for talent that you'd trust him to go throwing money around with?