/end rant
Now that's out of the way, I am curious about something. You mentioned Stall relying on frequent switching and all: how does your stalliness index correlate to how often a team switches in on the opponent? You mention how you can figure out turn / KO ratio. Can you do something similar like turn / Switch ratio?
Idk if you have time for all this, but you could go further. You could analyse the ratio of turns for the type of move you make. 'Offensive Moves' (Damage Dealing moves / Boosting setup moves for example), 'Defensive / Utility Moves' (recovery, hazard stack, toxic, burn), 'Switching' (when you switch something in and it doesn't die), 'Sacrifice' (switch something in and gets KOed, or you leave in something to die), and 'Others' (Double Switches, etc, I'm sure I covered most of my bases)
By definition, if you are sponging around by switching, you are making a defensive play. If you are sacking and attacking, you are making an offensive play. Instead of looking at the team you look at how they play. I hope this would bring up a very to-the-point correlation.
Unless, of course, if this is too hard to implement.