Not what I was envisioning. I was thinking that broke the Inner Sphere into chunks to size of a province, but the extent of these chunks doesn't respect existing borders, so, for example, you have one that included New Syrtis, but it wouldn't include all of the Taygeta Operational Area, however it might include chunks of the CC and TC. Now this effect covers the Inner Sphere, but not all of it, there are a few sections of it not covered and in reverse there are a few sections of the Periphery covered as well, probably most importantly the Clan Homeworlds.
And sometime before 3250 whatever was causing this effect stops, how does everyone react? Remember that there are now likely several copies of each IS faction, how do the various FS factions react to one another?