I think the player probably hasn't faced a truly strong opponent. But there aren't many of those, so the statistics look believable, especially considering he might have been playing since the beta in August. The stats were only introduced recently. As for Sacrifice, Stone Skin, and other abilities, why not? There are counter-measures for almost everything. Besides, Sacrifice, Stone Skin, and Earth Elemental are all very mana-intensive, and after 2-3 turns, they become quite predictable. Have you tried stunning the Spiderlings after they transform or delaying their turn? At the very least, it buys you 2 turns. And if the opponent doesn't remove the stun, you can stun the Liches for another 2 turns.))) In the end, who will deal damage in Sacrifice then?))) Be truly afraid of a Necromancer with Sacrifice in attack!

Added 14 minutes later
And also regarding the statistics... unfortunately, not everyone plays to the very end; some just quit. But on the other hand, what's the point of playing if everything is already clear? And on the third hand, I've won many battles in seemingly hopeless situations when only 1-10 weak units remain, and everything is decided by a single, random attack (these are usually the most interesting battles). And if such battles happen, it's not a shame to lose.