I disagree that skaven are less protected from attrition. In my experience skaven tend to have much deeper benches than elves and are also better able to hurt players back thus helping to keep a parity of manpower on the pitch which always reduces cas. Woodies and Pros seem much more likely to end up short handed in Skaven. In 10 BC seasons I rarely started a half down in players.
The wizard issue is tricky but something to think about is that if you start receiving the skaven/elf is more likely to have a full team and half in which to find an opportunity to use his wiz and what's more, if its not on he doesn;t have to take it, he can score quick in the second and then hope to get a defensive td on the third drive. Having 4-5 turns to score against a wiz defense is also not a great way to end a game.
On the other hand if you kick and defend well there's a chance you can put enough pressure on to make them use their wiz on offense thus giving you the chance at a relatively stress free 2-1 grind.
Most of the time elves can reduce their opponents to 1 or 2 hits a turn as every one of their linemen is AG4 and has access to dodge. Skaven linemen are AG3 and do not have agility access. Linerats go down the first turn, or the second, or the third. But they go down. That leaves their positionals exposed pretty much every game. Or at least that's how it works for me. I don't remember winning a bash war against elves, especially AV8 elves... They have better defensive skills and armor than skaven.