If you attend matches, you're playing against two things, the opposition manager and the match engine. The latter you can't do anything about - if it's decided to give you a bad match, then you're going to have a bad match.

This leaves the opposition manager. You can set your team up (formation, orders and tactics) to play against his team from the start of the match. If he doesn't attend, then you only need worry about what orders and tactics he has set, and after a short while you will be able to see what (according to the match play) they most likely are, and, if necessary. adjust accordingly.

If the opposition do turn up, then you will have to see what he does in match to play against you. He might change orders/tactics, sub players and/or change formation. If he changes formation, then you'll need to decide what changes you might need to make to counter them. If he changes orders/tactics, then hopefully, the match play will change and you can figure the changes out, and, if necessary, change to suit.

The match engine is the unknown quantity. We don't know actually what the engine has in it at the start of the match. The whole match play, goals, cards, injuries and then just plays it out with subtle changes to suit what the managers present have done; just a rough idea and then uses chance choices to affect the match play; or something in between. And Nordeus aren't going to let us know, either...

All I know is that I have affected match play by the actions I have performed in match. Sub a player who has got a yellow card, and count up how many times the sub has got a yellow card later - I've lost count, but by doing so I've prevented my side going down to 10 men. If the match engine had it programmed that I was supposed to play some of the match one man short, how does it react to not being able to do so? [...and yes, I've had the surprise red card for another player also...]

A goal down, 15 minutes to go? Change to hard attacking and you'll get at least one goal, in my experience. Did the match engine have that programmed in, or was it reacting to my order change?

I could list numerous times where
(a) I've had the satisfaction of being at a match, been in dire trouble and at least got something out of it because I've made changes and they've worked.
(b) I've had matches where nothing I've done has affected the match play or result in any way.
(c) And I've been badly Trolled, but usually when I've not been able to get to a match.

Please don't take the happiness of (a) away by telling me that whatever I'd done, I'd have got that result anyway...