Achieved primarily because they were rotated so extensively. Not only did this elevate their intensity in their game (Rose and Walker) but Davies's game too! I deliberately didn't include Tripps here as I don't think he ever dominated his opposite number (but happy to admit any confirmation bias I hold).
One of the most underrated players in all this though was Davies. Once Rose got his knee injury, Davies played every game! That in itself meant he had to manage his output, there was no rotation which impacts on his recovery and what he takes into the next game. I posted on here a while ago that since Davies arrived (14/15) at the club he has played to date 22 games more than Rose.
I liken Rose to that of Sissoko, I don't think Danny is a particularly technical footballer, like Sissoko his main attribute is his physicality. He will run over the top of his opposite number and do this for the entire 90mins. Best example I can think when he's up against a far better technical player but utterly destroys them over the course of the game was every time he came up against Belerin against Woolich. The early exchanges you would see both of them attacking each other, Belerin would usually have the better of him in the first 10mins or so, where he was capable of dribbling past him, or linking up well with one and two touches with his midfield. But then Rose would simply never stop, relentlessly running at him and as every min past Belerin would be pinned further and further back, if he did attack he was unable to cover back the space he left. Game over.
For me his best contribution following his injury was against Ajax in the first leg. We were getting completely outplayed, Ajax was brilliant, so intense and we simply couldn't live with them. It was Rose that stood up that game and got in their faces, gave them the game they didn't want. Foul after foul followed (drawing them in our favour too) crunching tackles, pure physicality/brutality, no skill, just brute force. He turned that game around for us IMO.