it’s actually 200mhz (had to fact check that) a 6% difference, which is surely made up by not having as many draw calls to do and hardly anyone has that as their fundamental limit anyways, when a game runs at 60fps (or more) on the X and 30 (or 60) on the S there’s clearly a ton of headroom. Almost all games on these systems are certain to be GPU limited on the Series S.
The memory is a significant enough difference to matter though.