If there was money on the table to invest better squad players I think he'd get us in the top 4. However I can't see the glass breaking. I don't think he's a miracle worker. Based on this season (and last), the way it's sloped since Christmas I think we will always operate just outside the top 4 places without that cash injection every summer.
There's 6 teams who have much better finances than us and when I say much I mean a huge gap. They can all spend £15-£20m on players and write them off if it doesn't work out. It's happened a good few times over the years.