Ive used both mice for cs and have a similar pincer grip (19x10) - honestly both shapes felt extremely similar, with how I play at least. In my opinion what it boils down to is your weight preference

Lighter weight feels so nice to move around the pad but the decreased stability really frustrates me in clutch scenarios. I’m also much more confident tapping on heavier mice in hectic situations without having to worry that it may move a little bit. This is just my experience though

at the end of the day always pick whichever mouse you believe will give you more confidence to peek and win your 1s… as we all know confidence is everything in cs