There are two reasons for having mulitple setups. One is to do the best for the technique you are fishing. Two is to have multiple setups in the boat so you don't have to retie every time you want to change a lure type. You need to think of the rod action and power, the type reel (mostly dependent on lure weight), and the type of line (braid for high sensitivity, mono for a little stretch and to not sink your line on surface lure casting). You didn't mention line, which means you have more to consider than you thought.
Your current setup will do for many techniques where the lure weight is sufficient for baitcasting to work. But when you want to go lighter, you need a spinning outfit. Go first with a fast action, medium power, spinning rod setup and it will be very versitile. For this one I'd use braid with a flourocarbon leader. It would be for finnesse, bottom fishing, jigs, tubes, drop shot, that kind of stuff. Not surface.
After that it's going to be up to you which direction you take. For surface and cranks you may want a medium power, medium action outfit rigged with mono so as to have the line not sink your lure and to give some "give" when a fish strikes a crank or on the surface. Match the rod power and reel type more to the weight of the lures than to anything else.
By this time you'll be pretty expert and won't need any more help.