I would not disagree but I would not fully agree either, because how could some defenders or defensive midfielders performed well at taking free-kicks when they had the free-kick special ability but not high values in shooting? The same can be said for the case of corner for example a DC with performing well at taking corners despite having relatively poor passing and crossing skills. Special abilities may be related to some hidden attributes too, and the best set-piece taker hidden attribute may have been assigned to specific players of a team. I felt the effect of mutants more in association matches whereby some scores get very high and unrealistic.