I'm not sure what changing variations actually helps do in a tournament situation. If you end up picking another variation, shouldn't you be expected to be counter picked back by your opponent?
Inferno is one of the matchups I think Sub GM struggles in, but it's one of my favourite matchups to play. It forces you to learn your opponents strong points and where they get the majority of their damage from.
Fullscreen, Scorpion only can get optimal damage that leads to the reset via minion grab, spear and ex teleport. So you can't rely on a projectile war and getting a random iceball to hit. You'll need to adjust and play a more cautious style inching your way forward, so that you can get a jump in on a spear or minion grab. And you'll still need to be mindful of keeping an eye on his meter to see if he is able to ex teleport on reaction to your jumps.
Close up, Scorpion has even more options, where you'll need to watch out for his overhead which can lead to optimal damage to a reset. I enjoy the close up range because it turns into a footsies battle, especially if it's a good Scorpion player not a gimmicky one.
To me, take the bad matchups and embrace em. Complaining about a matchup without putting time into is just as bad as all the players who shit on GM Sub since they haven't learned how to get around clones.
. Minion grab is easy to predict cause you see scorpion reaching for his skull. I admit that it has caught me once or twice during slide start up frames but I quickly adjusted and started jumping at him. It's all a matter of practice and yes his start up frames ARE SLOW on minion grab. This can be punished on reaction just practice against him.
