Van Persie signed in 2004. Since then they've finished either 3rd or 4th every season, each year they've lost one of their big players that you have mentioned above. Even with Van Persie out injured and losing Henry then Nasri then Fabregas, they've still consistently finished 3rd or 4th. So whatever Wenger is doing or whoever he is replacing them with is working whether we think his replacements are mediocre or not.
The transfer window is still open, who know's who they'll have by the end of it. Even if they don't sign anyone, they'll still be up there, Wenger as big a **** as he is, is a very good manager.
This is probably our best chance in years to finish above them, but its not a by-gone conclusion just because they've lost RVP.
They got 3rd last year because our manager's name was in the press every day with stories about him leaving, that derails a team completely. Every single time that happens the team he is currently manager goes to brick.
They also had the gift of Chelsea performing well below where their own finances suggest they should be.
There is also the fact that Liverpool, one of their previous competitors have seriously mis-managed themselves over the past couple of years and taken themselves out of contention.
So yes, they have remained in the top 4 while losing key players, but every year it's like they have papered over the cracks. They are there by virtue of being a little less brick than the clubs they are competing with. One of these days, constantly losing key players and replacing them with players that aren't as good will catch up with them. It has to.
Next season Chelsea are going to have to do something pretty special to emulate the fudge up of the season just gone, so they should be ahead of Arsenal. If we have the rumoured investment/hold on to key players/use the money to replace them well (something we aren't shy about doing but Wenger seems to be) then we can definitely finish ahead of them. Saudi Sportswashing Machine, if they get Debauchy have a seriously good team that may be able to challenge them.
It's happening, slowly but surely unless they change something, it will blow up in their faces eventually and they will finish 6th. One of these years, they can't rely on gifts from 2 or 3 different clubs that basically give them a free pass to finish ahead. If our manager wasn't linked away we would have been out of sight of them even this year.
The thing is though, because it is so obvious that something will have to change for them, I can see them eventually allowing this Uzbeki sugar daddy to have more control of the club and invest, because Kroenke's investment be as highly valued if they are falling behind a load of other clubs. If that happens, they will be back up again as a serious threat. And it will take a year of serious failure to make them realise they need to do it. So I think it will happen. In a way I'm quite glad that they seem to be content with carrying on as they are, papering over the cracks, and letting other teams roll over for them and letting them think everything is fine because they are still qualifying for the Champions League. As long as that happens, they won't address the glaring issues they have and change direction. But one of these days, the top clubs will be performing as they should do, and Arsenal will get locked out.