Arsenal needed Ozil more than I think others believe.
One too many times last season, we would enter the attacking third and just struggle. We weren't sure what to do, and really a lot of that had to with losing both RVP and Song (Song in his final season assumed more of a play making role instead of defensive role). We tried Cazorla there last season, but he's more suited on the wing.
Really, right now, we've replaced what we've lost in Cesc so I'm thrilled and really we're replacing Podolski. I know we were looking to acquire a 9 (and yeah, I read the rumors of Benzema), and I know Giroud has been on form right now, but if we're looking at being a top tier team we could've used a bit of reinforcement there.
To my earlier point though, I'm not too worried about having a CDM. Monreal has somewhat assumed that role and he's done well and with Jenkinson's continued development I'm pretty pleased with this one signing. I still think we struggle to finish fourth, but it strengthens our side so I'm pleased.
As for the Spurs improving argument. You can sign quality parts, but Bale assumes attention. Take it from a the standpoint of a fan who seen highly rated players leave. The field shrinks and world-class players can really make above-average players look greater. Losing Bale is big.
Lastly, I only watch Real to watch Modric play, and he had a fantastic game - about time. I still think he's one the wrong team, I still think that Mourinho nearly ruined his career (as he's about to do to Mata's), I still think that he needs to be sold. But still, he's rated highly for a reason.