You can't see your substitution rules after the match was played, you just have to guess or remember what they were.
The teams with the better players will generally win, but don't forget there is a large home ground advantage. So you need to be significantly stronger to be assured of an away win.
The formations definitely make a difference. They define where on the field your players will run to during a match. The wrong setup & you can easily lose a match you should win. You also need to look at the strength of the opposition. For example if your team is generally stronger, but your opponent has one or two good strikers - you need to go more defensive. If your opponent is weaker in the midfield, load up on your midfield to dominate & take advantage there. Also worth looking at your opponents recent wins & losses, what formation worked against them & what didn't?
You just need to use all the info you have & use the match analysis tool to give yourself the best chance of winning. And after you have done all that, there is still an element of luck & you can still lose the unloseable match & win the unwinnable match.