squabbling – Doggerel

OK, time to crowd-source a question for those in multi-dog households:

How often do your dogs squabble, tussle, or fight?

I think “squabbling” is the best word for what I’m thinking of — that irritated grumbling at each other that dogs do when a dog gets too close, accidentally steps on a paw, or is just plain annoying. Squabbling is definitely distinctive from fighting; a squabble ends pretty quickly and no one emerges injured. Teeth may be bared, but they are sparingly used. (A dog fight, on the other hand, is one of the most horrific things you can see or experience, I think; you’ll know it when you see it? Dogs won’t be torn apart from each other; they are tussling to injure.)

Pyrrha and Eden squabble on a perhaps daily basis, and to date, I have had to prevent 3 almost-fights from occurring. They get along, however, about 90% of the time. Is this normal? Or is this a bigger concern about their fundamental compatibility?

Surrounding factors:

Pyrrha is 2 years old and spayed.
Eden is 6 months old and unspayed (planning to spay her when she’s 10 or 11 months old).
Pyrrha is sensitive and anxious; Eden is confident and feisty.
Both dogs dislike backing down, but Eden is more willing to back down and listen to Pyrrha’s grumbles, which often helps defuse situations.
Eden will give Pyrrha muzzle licks in gestures of friendliness; Pyrrha submits to them.
Pyrrha play-bows to invite Eden to play in the yard. On the other hand, Eden initiates play by jumping and nipping at Pyrrha’s face.
Pyrrha is overall very tolerant (95% of the time) of Eden’s peskiness and adolescent annoying behaviors (allows Eden to playfully nip at her, nom on her ears, etc.).
They are always crated when we are not home.
They are crated in the same room, but their crates do not touch each other (on opposite walls).
They can eat in the same room, but they will resource guard from each other if something exciting or novel gets introduced. Pyrrha is usually the first one to back down if Eden challenges her over a resource.
Pyrrha can be possessive of me, but no fights/squabbles have involved me directly, from what I can tell.
They can drink from the same water bowl simultaneously with no issue.
They can sleep near each other with no issue, but Pyrrha will grumble if Eden tries to snuggle. (Pyrrha will do this with all dogs, though.)
We separate them from each other if we can sense tension building (moving them to other rooms, or one goes outside while one stays inside, etc.).

I know that they are beautifully behaved on weekends, because they get lots of exercise. We hardly have any squabbles or tussles on weekends. So, exercise and mental stimulation is definitely a mitigating factor.

But my fundamental concern is, What if they just don’t like each other? What if they never like each other? We’ve had Eden for almost a month now, and I’m not sure if this is something that will improve with time, stagnate, or intensify.

UPDATE: As I write this, they are playing happily in the backyard (play-bowing, lots of open mouths and happy expressions, lots of looseness). Yesterday was a squabble-free day, because they both got to run with Fiona for about 40 minutes. I’m realizing that all of this is closely linked to exercise and mental and physical stimulation, so I clearly have work to do to improve their access to exercise.

What do you think? How much squabbling is too much? How have you dealt with tension between your dogs?