IMO, Lennon has played very well in the last two games - unfortunately the only man he's had to pick out in the middle has been Defoe. Not ideal when he manages to beat his man so many times. I think the high line worked alright yesterday, with Livermore and Sandro protecting the defence yesterday there wasn't too many problems. But after Sandro came off, there needs to be some flexibility whereby the lack of midfield cover enables the defence to sit a bit further back - Gallas wasn't able to hold the line afterwards.
After two games I don't think we can really look too far into how well this new system is doing. Once we have done all our transfer dealings and AVB has a full squad to pick from, then we can pick apart the success/failings of the team. If you look at the last two games - a fit creative central midfielder like Modric would have made a lot of difference. And with the amount of crosses that were put in yesterday, a fully fit Adebayor might have taken the wind out of West Brom before they had got any momentum.
I don't think we're too many players away from challenging again. The problem is, other teams are at this moment! Come the 1st September, we can assess the squad IMO.