Hord should be somewhere beneath Yoda, probably around Plagueis's level (a notch below I guess). That's enough to give Luke a very good fight on equal standing, just like Yoda most definitely would, but unlike Yoda, Hord would be pretty much hopeless.
On the other hand, Nox should prove a sufficient aid. Prime Nox should be Vader+ level, but not Plagueis level yet (unlike prime HoT, who was already completely above Vader by beginning of Act 3).
I can't say if that's enough to bring Luke down. Kressh is a non-factor though.
Lol Ludo Kressh doesn't have any feats other than getting beaten by Naga Sadow so he's NOT soloing! Nox is impressive but it's hard to put Tulak Hord anywhere. You can't just assume he's the greatest duelist ever so I think he should be banned from further versus series. Kressh is a force wielder so it's also hard to include him. Anyway, Luke takes it.