As I said, I'm probably one of the hugest Ramsey fans on here and I know his best attributes, but I'm not blind to his limitations. Yes, his goals were crucial to our "title charge" in 2013/14, but let's not act like his injury was the only factor that came into play. Ozil, Wilshere, Theo, Chamberlain, all sustained injuries during the campaign, and left us with only a weak, jaded and tired squad to pick from during the run in.
Midfield control is achieved in two phases: What you do when you're with the ball, and what you do when you don't have it. When we don't have it, positional discipline, Ball winning and disrupting the tempo of the opposition, aka "acrobatic sliding tackles" is the very first step to controlling a midfield. Coquelin gives us that. When you're with the ball you need an Arteta/Cazorla type who dictates the tempo of the game. Ideally we would get a single player who can provide both, but hybrids like that are extremely rare. Is Schneiderlin that player? I don't know.
The team would lose its central midfield balance without Coquelin. That much is obvious to me. But it is also obvious that we need Ramsey in the side for the reasons you listed above. Wenger had a decision to make. He chose to sacrifice Ramsey and move him to the wings. And I can see why.
