I agree that archers, catapults crossbowmen etc. shouldn'bt be able to shoot two or more tiles away, just too unrealistic if you think about what one tile stands for in reality(no rock of a catapult or arrow of a bow flies 20kilometres) but for later ranged units like artillery and rocket artillery and battleships a range of 2 or even 3 would be ok.Cities shouldn't do any range attacks with miltary units and shouldn't be so strong without any military unit.
To solve the problem with the range:1 catapults I'd say to allow some melee units to stay with some ranged units, for example swordmen and catapults but if a tile with swordmen and catapult gets bombarbed , both units are affected.How many catapults would you need to totally fill a whole tile of lots of square kilometres?I think it's unrealistic that one catapult unit can't share the place.