Talk of massive transition etc is a bit much in my opinion. Harry and AVB are working in the same constraints, so AVB needs to follow Harrys' lead. Many on here criticize Harry, but like we are seeing now under AVB, it's hard to sign quality younger players. Gaps will always be left in the squad and therefore a good short term strategy is the best option. It's far better to sign older, free players like Brad, Saha and Nelson, that pay money for younger players, on long contract if they aren't the one's you really want. For example, if AVB can't get one of his first choice strikers this window, it's better to sign a Saha type for a year and having a go next summer, rather than spending £12 million on a striker that isn't ideal for him.
We finished 8th in Harry's first season and without much money or CL football, he strengthened the squad with some pretty unfancied players that summer and went on to finish 4th. AVB has to do the same. If we can't get the players we wants, he either has to gap fill with short terms older players or give the squad the balance it needs by buying less fancied names that he knows can do a job. Not many likes Crouch, but he did give us a different option and thus gave the squad a well rounded feel. Many thought Kranjcar was up to much, but he gave us something different to our other attacking midfielders.
Just because many of our fans don't appreciate Harry's methods, doesn't mean they weren't in fact the optimum way of working given the constraints placed on a Spurs manager. AVB has to look at what made Harry so successful and many of the reasons for that were things many of our fans hugely criticized him for. It will be tough for a lot of our fans to accept that, but it's probably true. If we don't challenge for a top 4 spot this season and we haven't filled in the gaps in our squad, there is no point blaming Harry or even Levy. Levy doesn't make things easy, but Harry has shown with the right approach (though hated by many fans) we can challenge. From what I've heard when AVB speaks, he seems like a bright guy and I have faith he can do it.
If we can't sign a Leandro type, then he has to be creative in the market. This could mean a short term signing. The same is true of the GK situation. If he can't get the keeper he wants, he should wait until next summer and Brad will be fine for another year. If he can't sign a big name right sided forward, then he shouldn't be afraid to go into the loan market. If a quality player suddenly becomes available at the last minute, he needs to be prepared to accommodate that. These are just the things a Spurs manager under Levy needs to be able to do. At the end of the day we've finished in the top 5, 3 seasons in a row and he'd be a fool not to look at how the previous manager was able to do this, even if it means tinkling off fans.