I know it's an old one but it actually bothers me.
Using Rosetta is OK, but not that big improvement. Machine is Mini 9400m and 320m. Seems that 9400m is better then 320m. Seems that High-Quality uses a shader or something else that causes this issue.
Is it possible to do a better config over a cfg-file?
IIRC, COD 1 & 2 were released on the App Store for Intel based Macs a long, long time ago (January 2012 to be precise). No need for Rosetta.
Trouble is now of course, that old 32 bits are no longer available. Sure there is no other way to get hold af a Intel-Mac version of the game?