I've only used two types of trolling setups ...... single jig or Roadrunner, or a crankbait pulling a jig. The single jig/Roadrunner setup was strictly for Crappie .... the crank/jig trailing setup was for Hybrid Stripers, but caught Crappie on the jig. I don't really use the trolling method much, just on certain lakes and at certain times. Most of the rest of the time, casting a jig or Roadrunner to a specific target is how I catch them.
On Weiss Lake (Ala) - slow trolling single or double jigs, without added weight, is pretty standard for pre-spawn fish. Guides and locals generally use the "spider rig" setup, when the fish are along the channels or in the flats. They just adjust boat speed to allow the 1/32 or 1/16oz jigs to reach the desired depth.
I used to fish Green River Lake (Ky) most every Spring ...... trolling a couple of rods out behind the boat, under trolling motor power, using Roadrunners. I would troll over the sand/mud flats in 6-8ft of water. Caught a lot of nice fish doing that, and when I found an area where they seemed to be concentrated - I'd fancast the area with the Roadrunner.
Flatline trolling has its merits ... given the right conditions and terrain. Adjusting boat speed, length of line out, and jig weights is important, as it allows you to maintain proper depth presentation.
I "prefer" to cast jigs (dock shooting included) ... but, when faced with the situation where others are catching fish, using a different bait or method, and I'm not doing as well -- I get like 'em or as near as my equipment will allow :D .......... luck2ya ..... cp