With the continued reduction in player base opportunities for viable plunder targets have shrank substantially. Pumping out side of post war CF is nearly impossible for mid level kingdoms, an honestly sitting for weeks doing very little scouring the server for some reasonable plunder just is not enjoyable anyway. I am not advocating for the gold free for all that currently exists in Genesis, but their needs to be a more consistent way to supplement the income that used to be available via plunder.
I would propose an untargeted attack type, where you have to send a certain portion of your total offense out, for a similar length of time as a plunder would encounter. Troop losses should track closely with a plunder +/- some random factor. In return you could immediately loot an amount of gold that should exceed your troop losses by some amount with a random additional bonus where occasionally you get a much larger return... also occasionally return no gold, or a reduced amount.
I am sure some people smarter than I can assist with appropriate balancing number to make the idea viable... just hoping the idea has merit since there is a reasonably large economy hole right now out of war that really makes the game far less fun than it should be. Playing around in genesis really drives this home when you can consistently grow, and actually have the ability to sustain troop losses from being active.