1. She always has pokemon.
2. It's a stable income; extra money has never been a problem.
3. Digging up the main hero in the first week isn't an issue, at least 6 heroes will be bought. Any Barbarian will do, or actually any warrior. Plus there are prisons. In the worst-case scenario, getting the Pope by the 2nd week is no trouble, but that only happens in a few layouts.
As for Valeska: pokemon never happen, she ends up with little cover and doesn't represent much striking power and regularly melts. Two useless skills that slow down her development (I don't deny there are cases where shooting rules in FB, but more often off, def are needed, and you can't take archers into the Dragon Utopia), leadership is just removed by negator and that's it — no slot. And then there's the possibility, when there are no restarts, that Valya has only 1-2 stacks. I prefer reliability; that's my imho :).