So, my friend and I are planning a breeding project hoping to get some muties. We'll be using his Felis king as a stud for a female of mine (not primal) with similar coloring.

As of right now, the idea is as follows:

1. Breed my lioness, then terminate with CRB (already done)
2. Lower her fert to about 10% with tackweed
3. Feed her a GMO Cow
4. Feed his stud pennyroyal
5. Breed and cross our fingers?

We're both relatively new players, so I thought it'd be best to double check with some more experienced players to make sure we're understanding the breeding mechanics. None of these breeding items overwrite each other, do they? Assuming they do all stack, is this our best course of action for breeding for either Primals or lethal mutations?

Thanks!