I don't get Hayate/Vivio. I mean, sure, pre-Vivid pair the spares, shippers gonna ship, whatever, but Hayate comes with a harem.
I mean, the only reason not to ship Hayate with one or more of the Wolkenritter is that you think the power imbalance in a master/servant relationship makes that icky — which makes turning around and coupling her with her friend's preadolescent daughter a little boggling.
(I exaggerate, of course; there can be other reasons to not ship HayaRitter. But the fact that they're sworn to her is the most cited reason I've seen.)