In a brilliantly coached high pressing team ?
For the last year in games with and without Maguire we have seen what happens when you have a high line with a poorly coached press.
If you are in a high line team with a poorly coached press, does it help to have two fast centre backs. Marginally, because sometimes they might get a last ditch tackle in.
If you have a high line team with a well coached press, does it help to have two fast centre backs ? I would say it doesn't make a major difference.
All else being equal, you want every player on the pitch to be the fastest man on earth. But all else isn't equal. Bailly is faster than Maguire but brings less on balance, in a poor coached press but more importantly in a well coached press, which we don't have today but hopefully will have.