How much squabbling is too much? (Time to separate?)

[Periwinkle]

I recently rescued a Male Campbell's dwarf pair from an accidental/unwanted litter. They were weaned and turned over to me at 3.5 weeks, and I did not witness their first squabble until a couple of weeks into ownership.

I have been keeping a very watchful eye on their fights and they seem to be over dominance (no signs of injury). However, I find it seems the dominant hamster doesn't know when to stop. He will flip the submissive ham over, let him squeak, then not 5 minutes later he will do it again, chasing him around constantly. And doing this multiple, multiple times in the night (the cage is near my bedroom, so I hear everything that happens very easily.)
To me, this almost seems like it's happening too often? I have doubles of everything, and they have over 1000 sq. Inches of space. I also have a backup cage ready to separate at a moments notice.

They still play together, bathe together, and sleep together approximately 50% of the time.

Although there hasn't been any blood drawn, I feel as though the submissive ham is probably stressed with his brother constantly doing this to him. It is also annoying for me to hear this 5 times per night, and have to get up each time to see if all is okay.

What are you guys' opinions? What would you do?