I agree. This is very much a fixable problem for you, so you don't have to panic. (This I know a little more about than health issues
Most of the time, you'll have scuffling and chasing going on when new mice are introduced. They have to go through it to establish dominance pecking order. As long as there is no blood, let them work it out. I had pecking order scuffles all the time.
I only had a serious problem with one of my mice where blood was involved. She was younger than the rest and I put her in the cage with the established colony who'd scent claimed the area. They chewed her butt bloody.
She was in shock and was bitten severely and had spent the night perched precariously on a ladder because that was the only place they didn't chase her. I was so ignorant at the time.
So, I separated her until she healed and grew a little bigger.
This is what I did next and it seemed to work.
I rubbed her in the urine soaked bedding from the main cage so she would smell like the other mice.
Then I rubbed the other mice in her urine soaked bedding so that they smelled like her.
Then I went a step further and blended the dirty beddings form both cages so that the territories of both cages smelled like everyone.
After they had a night to get used to the concept, and get used to the new smells, I then emptied out the main cage, cleaned it within an inch of its life to remove all traces of scent that I could, and put down new bedding. In this new neutral territory I re-introduced my butt-bitten girl and watched them carefully.
Now that she was bigger, the first thing she did was run roughshod through the entire cage scuffling with, dominance pinning, and peeing on everyone until she'd proven that she was the top mouse in the cage.
There were no problems after that.
First you need to make doubly, triply, sure that what you have are 3 does, and not some kind of combination of male/female. Any males, you will want to separate and keep by themselves in a single cage. Males kill other males, and breed out of control with females. Problems I'm sure you don't want to deal with.
If it's just pecking order scuffles, let them work it out. Keep an eye on them in case blood occurs. If it does, remove the victim.
If my above story doesn't work for you, try introducing them slowly over a few days one at a time to each other in different combinations. You may figure out that if one accepts Asuna, the other one will fall in line.