The Titans aren't a Pantheon, or, there's is the only one

They are Arcane and are susceptible to Fel, which is how Sarg was able to smack them all down. You are correct about them not being purely Order aligned, though. There is clearly more to them than ORDER, ARCANE, REINHARDT, REINHARDT, REINHARDT! HAHAA!

There are at least some superficial similarities to the constellar to consider as well.