Basically whenever I play FM I often try to make leagues as competitive as I can without completely destroying any balance to the league itself, so often what I do is I go to a country, such as Bulgaria or Ukraine for example (where 1 team basically wins the title every year), which I never play in the domestic league and will edit the players in a lot of the leagues, simply make them a little better so that they aren't as good as the best team in the league, but where they are much more equal. 

So often I'll just (usually for younger players) make them better, like a simple increase in Current and Potential Ability (some more stuff, this is just an example), now I've made presets for this...the problem is that a lot of teams have players who are better than the presets, higher CA and PA...so I can't use them and have to do it one by one.

I must have done thousands of players like this, I do this with almost every European and South American league...

Is it possible to make it so, if I highlight 6 players in team list the preset will only change those specific 6 players instead of the entire team?

read page 3 of this thread explains making individual presets, can use it for several players at a a time rather than a team