Technically they are only betting against at maximum 3 Russians for Olympics/Worlds.
True, but those three from Russia would be chosen as the best of the best, most consistent, healthy etc from a bigger group of talented young ladies. Whereas other country would have to send the one, two or even three without being able to choose. So if if the skater from the other country has a growth problem and become inconsistent, or another one become slightly injured (perhaps not even seriously but enough to affect her level of skating), they have no choice but sending the skater anyway, whereas Russia will be able to choose the best and the most in shape skaters. That makes a huge difference. Look at the two Chinese ladies. One year Zhang was good, the next year Li was great but Zhang was not able to achieve her past result, and the following year neither of them were that great. In a country where they have only 1 or 2 great skaters that can easily happen, whereas Russia will be able to send someone else who will be pretty good.