If enlisted soldiers revolt against the officers, I don't see that working out the way you're describing. If loyalty fractures along party lines, there will be

If enlisted soldiers revolt against the officers, I don't see that working out the way you're describing. If loyalty fractures along party lines, there will be two chains of command, and I don't think it would be remotely difficult for the two structures to reorganize themselves. The police do have a strong and unified party preference, even in the most left-leaning cities.