(Sorry to carry on with the percentages but) problem is if each player contributes 2% to the teams performance, that's a 22% improvement in their own performance i.e. more than a fifth, which is massive. You could be right but this means a real step up by each and every player. Improvements in things like fitness, skill, speed, sharpness and attitude could conceivably add up to 22% overall improvement in a player.

But I agree there are specific things that need addressing (though we may disagree on what) rather than just some vague notion of "performance".