It is a brilliant find of stats this. Well done.
MUFC, I have always thought this. I can see why players are brought on for 3 minutes at the end of a winnign situation to wind the clock down, etc...but bringing someone off (resting) not tactical change with 40 / 30 / 20 mins left, is pointless. The rest time usually of three days should be enough to recover in time for the next game.
People always quote the days before sub's, I wasn't around then, but have read numerous articles about it, and personally I think it is currently hindering the Manchester United team, squad rotoation I mean. Recently we had a thread about 7 subs, in the EPL, this bollox would make it even worse for us.
Salf about cold or rusty systems and players, you are again spot on.