Q:
Do the elder dragons compete with eachother?
They are acting individually. But this doesn’t mean they’re rivals.
That’s really all we know for certain. We don’t see them attacking each other actively, but we know that minions that happen to wander near each other will fight to the death like when they meet any other living being. We know they function individually and don’t have a hierarchy, but this doesn’t mean they’re not friendly.
The only in-game case of dragon minions interacting with each other is Crucible of Eternity, but here they’re all under the control of Subject Alpha who was corrupted by the energies of five Elder Dragons (and control those five dragons’ minions). So that’s not a proper example for that.
Stop treating GW2 as a single story. Each Season and expansion should be their own story.
I personally believe they’re all rivals. Otherwise Kralky and Prim would have came to save their sibling Zhai. I also believe all of the dragons have a strong dislike of each other, though will not go out of their way to screw each other over. Otherwise they would have been at each other’s necks already. Kralky and Prim come off as me as two dragons who love to manipulate events (in my own mind) to their own favor, so don’t be surprised if they’re two of the final dragons we take out. Hell, I won’t be surprised if Prim creates a path straight to Mord with his minions just to make it easier for the Pact to get rid of a rival.
PvE Main – Zar Poisonclaw – Daredevil
WvW Main – Ghost Mistcaller – Herald
Another angle to look at it would be to question how intelligent Elder Dragons are. Now some believe (with evidence I will admit) that EDs are intelligent/ sentient creatures. If this is the case I imagine they would have alliances of convenience, although these would be rare if at all.
Now if we believe that EDs are mindless forces of nature bent only on consuming magic (some evidence as well, although this requires us to place tactical and logical choices on the Champions) then they’d be actively competing for the same resources and have no reason to be diplomatic about it. So they’d only attack each other when they come across each other, but have no active rivalry.
Of course the nature of there relationship needs some consideration since magic being finite inevitably they have to come into conflict each cycle when magic starts running low. Since they’ve been around for at least 2 cycles it’s possible that there use to be a whole lot more of them.