Something often overlooked, I am sure there was a quote somewhere claiming that the Windrunners of old could "bind the storms to themselves" or something similar.
Considering Kaladins nascent ability to divert the stormfront at only the 3rd ideal, I would think it entirely possible that a 5th ideal Windrunner would be capable of at least breaking off their own mini storm, and a group of them capable of all but summoning a high storm to their location at will.
If this were possible, it stands to reason that an endless supply of stormlight would be within reach already, and given their status as military leaders among the radiants, it seems the ideal situation for them.
Edit: Found the quote from Syl.. "Men who walked on walls, men who bound the storms to them. Windrunners. Why would you want to be rid of something like this?"
