Ya definitely. A DM is the most important thing this summer, if we get a good enough one, it could help us compete next season. Because imo a ball winner in midfield can make a hell of a difference (Real Madrid and Lassana Diarra for reference), and we already have a lot of attacking talent.
Only problem is, Denilson and Diaby are huge favorites of Wenger's. He's gone on the record multiple times praising the former and calling him one of the best and most underrated midfielders in the EPL.
I don't think he'll go for a DM this summer, which means that the only thing we'll be competing for, is 4th place.