The game have a stabikity, and isn't too much paranoid with these things... usually, the game select 1 single better player for FKs that performs better -even without SA- for some weeks, same for corners, I always do tests to find that man, a single one for right-left position.
Main general performers, is way complex to explain cause it depend of the team confiiguration, if theres a 1* key player you can perfectly see how the roles I was talking about in the other thread, aren't assigned.
So to resume what Ive experienced, you can have a single key player, performing superb -+1 goal per match, visible always-
or, 2-3 high contributive players, that will alternate the protagonism during the season,
or, "0" key-high contributive players for some reason, so in that case, probably you'll feel how the matches aren't fluidly in your favour, or simply you'll miss all chances in the animations.
This last situation is happening to me lately.
The solutions for the last "issue" are, basically, cause Ive exerienced the same seasons ago and I resolved that problem, change formation, and check out low avQ players that are contributive to sell them, to have free roles of contribution that can be taken by the new signings.