ill pre cursor this by stating that I’m playing Pro difficulty. I don’t believe Fatigue is a factor at all the only time I have made changes are when they’re forced through injury. There Is an opportunity here to really have fatigue make an impact on the outcome of games. If fresh props come on in the 60th minute for a team and the rival has their starters on there should be a difference at scrum time. Maybe even the scrum goes down and penalties are awarded and if it goes down again maybe a yellow carded . Bringing on a fresh 7 to win some ball or a leaner quicker 12 or 13 because the big burly opposition is fatigued and you sense you maybe able to change the game with an injection of pace. I am playing 10 min halves I’m assuming it’s relative .