Stan Smith would probably either be a B or an A in my eyes. While he does do some pretty messed up stuff and tries to mold his kids into his ideal children, he had a massive redemption arc in the late-FOX and TBS era.
Homer shouldn’t have ranked so low. Peter honestly doesn’t give a crap about his kids meanwhile Homer actually does care about them. He doesn’t know how to properly be a parent and he’s abusive to Bart but he’s much better than Peter and doesn’t deserve to share a rank with him honestly.
While Homer has become an awful father, it is straight up offensive to place him in the same tier as Peter Griffin. Homer should most likely be C here so that both D and E are skipped before F with Peter