...keep all the 2-* wolves you have, cull[kill] the rest[all no-* and 1-* wolves] and you should have only 2-* wolves moving forward. It shouldn't take long at all to regain a large population of 2-* wolves.

I've kept all my 2-* boars I have at my hogFarm and have never had any regressions with other 1200 days, but only have single star wolves breeding at another base. Wish I could tame some 2-* wolves, the nones are so weak...