I think the covers actually HELP air flow/cooling . AND...the left one helps keep grass clippings away from the f wheel cover .
A problem , IMO , is it seems like there could have been a better way to fasten them to the pedestal & hood support . A lot of guys simply left them off & they ended up discarded .
If you WANT to address a real problem that can cause overheating & actual engine fires , you should remove the sheet metal covers on the engine . Mice nests are commonly found in the spaces there .