Mearsheimer guesstimates at least 2:1. I think the 10:1 number is part of a game of ever more exaggerated claims by the posters from either side.

Logic:

some guys claim 10:1 artillery shelling at some point ⇒ extrapolate to all times and places, ignore other people who say 5:1 or whatever ⇒ since most people die from artillery shelling this means 10:1 losses/dead