If I ever get motivated enough I will record a few hours of games. There is a very discernable pattern when it comes to landing these stuns (and maybe other things, too). Ive begun actually planning on stuns to fail, so I can ride the rng. I literally change my plays once the rng swings to stop stunning and its working for me.
That said, I dont think there is any correlation to wins/losses/trophies that I can see. I cant tell if its number of games or time interval (seems to be number of games, maybe within a time interval) but something is definitely off. Really hoping we get an update on it come 1.6.
That said, though not entirely related, I reiterate my suggestion - please up stun chance to 85% and adjust dmg modifiers as necessary to maintain balance.