A quick question/Advice needed

OK, so one of my friend's challenged me to a friendly.
I'm not complaining because I got a good amount of skill pts
But I trained all my players with just enough condition so that they were supposed to get 95-99% by KO

Videos for Rests aren't rewarding me neither :mad: just need 1 more pack to rest the team

So my question is this: Is it better to play my reserves in place of my lowest conditioned players?
In this case playing slightly inferior players out of position and/or changing to an unfamiliar formation JUST to fit players with say 5-7% more condition.

That question asked, is there a more general rule of thumb for playing reserves? ie x% better condition etc etc