My theory on Como. Decker and Constellation -- which I've stated before so forgive me if it sounds familiar -- is that four starships form a cruiser division (to use a WW2-era term, you may prefer squadron or group, whatever). Three are commanded by captains, but the fourth has a commodore who has a second hat as division commander. Since starships normally patrol alone, the commodore usually acts like a normal starship captain, aside for some extra paperwork as division commander. But if the division is assembled to act as a task force, as in "The Ultimate Computer," the commodore is in charge and his ship is the flagship.
Yeah, that's pretty good, too.
What doesn't quite fit is that the subject of the Enterprise
belonging to Decker's squadron never comes up in the various arguments for who has command of the Enterprise,
between Kirk, Spock, McCoy, and Decker. I suppose one could try to argue that the Enterprise
is from a neighboring squadron, but that doesn't seem too likely, to me, especially with only a 12 ship fleet.
If Decker as squadron commander had been the intent, then it would only have taken a few minor tweaks of dialog to make it fit perfectly with the episode. While technically an argument against the idea, this last point also shows how not too far out at all your idea is. For that reason, it's a pretty good idea.
P.S. No, I hadn't read your idea before. Thanks!