I won't exactly compare Super Robot Taisen OG to Final Fantasy 8, considering timing is small aspect for that game. You have more timing in Mario Rpg, Paper Mario, Legend of Dragoon or Magical Starsign. Some might say it's closer to other turn based action rpg like Valkyrie Profile(ps1,psp) or Eternal Sonata turn-based action RPG. It feel more like a borderline fighting game with a RPG formula.
There's a heavy emphasis on timing so you can juggle your opponent and implement varies combos. You can rotate your party members to increase the combo length. Of course, long combos = high damage. Or you can sacrifice a few combos by canceling your attacks. If you time it properly, it will result in an increase to the special meter for special attacks. To cancel, you have to proper time your button press or look for visual cues. Most of cancels varies with each move or character. Also, Super RoboT Taisen OG is bit more streamline or simply compared to Cross Edge. If I recall, you can select up to 5 combo attacks. The combos are really easy to set up. Just select which combo you want first to last.
I think the problem with this game is there are too many bosses in this game(About 3 boss per dungeon, similar to Wild Arms 5) and some of boss battles are really long. They can be up to 10-20 minutes. It's annoying that some special animation attacks can not be skipped like Cross Edge.