I recall the Shatnerverse novels, where Mirror was the control universe and Prime was the version endlessly tampered with by the Preservers. I really liked that
Every alternate reality in Trek is intertwined. Canon evidence is the same people interact in the same places at around the same times despite massively different circumstances. For example:
Seven replaced Kes in a Jeffries tube with Tuvok scanning a Kremin torpedo in 2 timelines. The reason for scanning the lodged torpedo was different but it was identical.
The Enterprise-D was felled by a Klingon bird of prey via warp core breach in 2 timelines, 4 years apart.
Kirk or Spock sacrificed themselves fixing the warp core in an incident involving Khan in two timelines,15 years apart (and indeed, the entire Enterprise crew coming together in very different circumstances 5ish years early)
The Mirror universe characters are always in similar places and situations across 225 years of in-universe history as Prime. Only one time is it justified, when Lorca arranged the Prime people he'd need for his attempted MU coup.
There was almost an explanation in 2009 Trek, a cut line where Spock suggests the timeline is "healing" itself. But "City on the Edge of Forever" says similar:
SPOCK: There is a theory. There could be some logic to the belief that time is fluid, like a river, with currents, eddies, backwash.
KIRK: And the same currents that swept McCoy to a certain time and place might sweep us there, too.
It's magic!