One of the reasons I despise Egypt is their chariot archers. Yes, I definitely try to keep my slingers out of their range. If I have straight up missile units vs inf, I almost prefer slingers to archers. Although slingers definitely require more attention due to the fact that you can't have them behind your line of infantry. Against chariot archers, good archers are the way to go. Not sure what kind of range Cat Archers have, but I do like them against Egypt, because then I have a heavily armoured, very mobile archer unit; one that can go toe to toe with chariot archers.