Well, there's about half a dozen worlds in the Glisten Subsector that have "politically significant" Aslan populations after the invasion that didn't before, plus 4 worlds (Aster, Craw, Wurzburg, & Sorel) that are flat out "Aslan Worlds" afterwards. There's several more new Aslan pop worlds in Trin's Veil. If you throw in Gazulin, Tobia, Pax Rulin, and Usher subsectors that aren't in the Marches but are in the Imperium, there's a bunch more. Including Tobia and Gazulin, both subsector capitals and major population centers.Glisten was never taken.
View attachment 1747
Look carefully at the worlds that are "taken" in the Spinward Marches.
How many are Imperial worlds...
what was the population of the worlds before the Aslan "invasion"
how does a fleet of second hand TL12-13 ships defeat the TL15 forces that can be brought to bear by Norris? Glisten monitors could wipe out any Aslan threat.
We can have a pointless and unresolvable argument about whether "rooted out" means "stopped before they got anywhere" or "removed after they did" as far as Glisten goes. But they did conquer Aki (for a year or two) and Sorel (permanently), worlds adjacent to Glisten.
The idea that there are enough Ihatei around to accomplish that kind of invasion at all, much less in the couple years the timeline allows, is bonkers, imho.