that's a myth. it's just as easy to flick to heads on a low sens as it is on high sens (quake and overwatch players all use 30 cm/360). the only tradeoff i've experienced is that high sens gives you better movement, bigger flicks/180s, but shit tracking so holding down an angle is harder. in other words: if i am peeking a target, it's a bit easier to flick to them (high sens entry fragger). however, if i'm stationary and holding an angle waiting for someone to peek me, i would miss sometimes because tracking is harder.
low sens is better overall for CS i think since positioning and holding angles is what you should be doing 90% of the time instead of running out flicking everything. but high sens sure as hell is way more entertaining cuz 180 degree flicks boiii