Arsenal's Strength In Depth

I feel that last nights Carling Cup win over Sheffield United justifies Arsene Wenger's decision not to buy big over the summer. Wenger's come in for criticism in the past for his limited and youthful transfers with critics saying he could come to regret his decisions.
But how can any Arsenal fan complain with their side sitting top of the Premier League table and the youth side thumping six past the blades last night. With an average age of just 19 in last nights game, Wenger has proven that you dont need to buy big in order to be successful. Arsenal's record signing is £13 million for Sylvain Wiltord who they brought of Bordeaux in 2000, but compare this to most other top clubs and there way behind.
Arsenal are now the only club in the top four not to be owned by a 'sugar daddy'. This is not just in reference to the Man City takeover but a trend that is manifesting itself in the Premiership!
I believe the Arsenal first XI are good enough to beat anyone. But injuries are inevitble, with Robin Van Persie and Thomas Rosicky regulars in the treatment room. Even summer signing Samir Nasri has been out of action for a few weeks with a knee injury, but the Gunners have strolled on and havent seem to let injuries affect them.
It was understandable that Wenger didnt spend big over the summer because of the massive debt they owe through moving to the Emirates. Not only that but wage improvements have also halted their activity in the transfer market. Wenger spends less than mid-table teams yet Arsenal are constantly in the top four, running Chelsea and Man Utd to the wire last season.
I predict trophies this year, with Nasri, Vela, Walcott and Fabregas to shine through out the campaign. However with all this said, i would like Wenger to sign a defensive midfield player to take the pressure of Cesc. We dont need a world class midfielder, just someone with a high work and tackling rate that will do the job required.