There is some slight glove swim, but there is also debate about how big a problem glove swim itself is.
Glove swim is more of a symptom rather than an independent problem. The main cause is incomplete or asymetrical adduction most often from a lack of core stability or strength.
The biggest problem in talking about FSR is the focus on the plant leg because this is the easiest to spot. A lot of coaches will say the front side resistance is good because the plant leg looks good and address the glove swim as if it were a separate problem. Instead all that needs be done is recognize that FSR starts with the plant foot and leg, but does not end there. Simply follow the kinetic chain from the plant foot through the body and into the ball and make sure the body stabilizes before energy passes through (leg, hips, shoulders, throwing elbow) and "problems" like glove swim will disappear without ever being directly addressed.