There will be a lot of people falling for the "Gee, Knackers from North went really well today. I've got to get him into my team, no matter what!" trap.
There will be a good handful of players that score way higher than they normally might, due to the underdone opposition.
My suggestion?
At the end of the game, revert all the North scores using something like this:
Expected SC scores under a normal game: Nth 1600 v WC 1700
If it ends up something like 1950:1350, then you need to reduce the Norths players by just under 20%.
Ask yourself. Would you still be as excited to get Knackers into your team, if his 100 was actually an 80?