As said above, SAM loose 5 kenki on their two 3-skill-long-chain finishers, which change their Kenki generation from 50 over 8 skills to 40 if they stand in front, or 45 if they just stand in back or flank withouth moving (At least one of the two positionnal will hit right).

Since they already get plenty of kenki to buff midare-setsugeka, they effectively loose 20% of a Hissatsu : Shinten for every missed positionnal, translating into a net 60 potency loss.

I, however, don't have the overall potency of a full SAM cycle to translate this into a % loss, but due to their high potency skills and high DPS even from non positionnal SAM, I would say it is far to be big loss, even if it is still a loss.