Well, I wouldn't say bad, but anything with Arden is completely inferior to the exact same pairing with Lex. Chances are you won't really want two characters with Ambush, so Arden thus often goes unpaired.
Alec is in a similar situation with Beowulf, but there's the off chance you might want Awareness over charge, or want to pair both of them due to Pursuit. Doing Lachesis/Beowulf and Alec/Briggid so both sets of kids have Pursuit is one example.
Midir is only really good if paired with Aideen, and even then his so-so stats sort of drag Lester down, though Lester gets over it due to having both the Hero Bow and likely the Killer Bow to murder people with.
Other than that, just pair a mage father with a melee mother or vice versa, with the obvious exceptions of Azel/Lachesis and Lex/Tiltyu aside, due to Lachesis having two magic sword capable kids and Lex/Tiltyu giving Wrath + Ambush hilarity, and Aira doesn't count because her kids (or Lakche at the very least) are literally unscrewable.
Funny enough, I did a run with Claude/Aira once. Lakche and Skasaher were still killing machines due to their high base stats from Aira, arguably even moreso due to the fact that they were basically 6 Mov mages (magic swords, remember) who could attack physically pretty competently, AND had Astra. Plus Skasaher had the advantage of Major Blaggi, so he was magekiller extraordinaire.