If we replace the manager and continue with the model of making a profit on the back of transfers we are unlikely to obtain one of the calibre of Wenger. The reason being, that Managers of that calibre aren't likely to be willing to do that!
That isn't to say that there isn't anyone out there, because I reckon Moyes could do it - he kind of fulfils a similar role albeit on a smaller scale at Everton. But the strategy we employ is the constant selling off of our best players - this is why we've had teamsheets that are regularly unrecognisable from the teams that preceded them three years previous. This repeats itself all the time - which is why we see the on pitch problems repeat themselves time after time. We see the same thing EVERY season because we are always watching a team of players at the same stage of development in their careers each season. We never mature as a team, because players are either sold on at a profit if they develop or shipped out on loan if they don't.
We'd get the change we wanted to see - but only in the short term because the problem is (IMO) the over-riding strategy employed since the ownership change will lead to the same frustrations occurring.
The Board - and Wenger seem to point to what is going on as a prudent, sensible approach, but it is not - they will always be able to trade off the the goodwill of the vast majority of existing supporters, but long term, where are the new supporters going to come from? Continued in perpetuity, this is a strategy doomed to failure because failure on the pitch is eventually going to lead to failure on the balance sheet - but I bet my ass the Club will be sold on for a tidy profit before that occurs.
I'm sorry for the ramble, but the crux of my point is this: we may see an improvement with a change of Manager but we will not see a change that addresses the fundamental problems until the current ownership realises it is at the point of profit maximisation and sells off accordingly.