rod length
Let me start by telling you that I do things a bit different sometimes and this is just my opinion. You already have the short rods, but does at least one of them have 4lb hi-vis line on it. My last 2 trip I have seen 60% of my hits rather than felt them. If you can't see the subtle line movements you are missing fish.
The next rods up the line are the 6' to 7', of these I have many from light to medium fast action. To each it's purpose. Keep in mind that it's easy to tear a hook out of a Crappies tender mouth. My stiffer rods are for vertical jigging with heavier jigs, 1oz or more. I also use them to troll crankbaits with. The softer ones I use for float and fly, casting, and anything else with lightweight artificials.
Then we come to the long rods. 8' to 16' in length, most folks use these for spider rigging or vertical jigging. I think the spider rods are a bit stiffer due to the weights use to keep the jigs or baits at depth. Vertical jigging with light jigs take a sensitive, balanced, comfortable rod, cuz it's going to be in your hand most of the day. Not too soft cuz you still have to get the fish out of the cover, but definately not bony.
That is the best I can offer, and there is no 1 rod standard to suggest. Too many variables; budget, cover, reel preference, and so on. If I had to have just one for my style of fishing it would be a 6'medium with a soft tip. I would have to have 2 spools with 4lb and 6lb line though to cover the bases. Good luck with your search. I have 21 rods hanging from the ceiling of my shed and use them all. Tight lines.
Creativity is just intelligence fooling around