i have actually already written an simple one that works with ians pathfinding and also some tweaks to get ians one smoother.
its an simple object that i give two limbs that i position a bit in front and on each side.
and as soon units collide so do i position the dummy object at the position of the one that moves fastest and give it the same orientation as that object and the calculates wich limb is on the largest distance of the opposing units centre.
to decide if the unit should move to the left or right to use the shoortest route around.
dont think this makes much sense but its my current version for the soldiers.
as it seams right now will i not nead dark ai for my rts but it will be usefull for another project later on maybe.
almost forgot i use an vector based distance calculation to check if units collide that gets right distance by adding and dividing the units that the soldier collide with its x and z size.