Shared Armies in Galactic War: Double Standard

I was just playing a 1v3 in one of my Galactic Wars and I spawned on the same planet as one of the sub commanders. No big, deal, I rush him down and a good portion of my (ammo tech! truly OP) doxes blow up with him. Unfortunately, this does not blow up his armies! This becomes a problem later as two other planets are fully economized against me and I didn't get a chance to expand on my own planet.
I don't have any current Wars with sub commanders in them, but I don't remember having control over their units. I'm NOT asking for that! Rather, I just want to suggest making enemy sub-commanders follow the same rules and have their armies self-destruct appropriately.

Would be an idea, but only if sub commanders are playing VERY defensive then...
...the AI generally tend to manuver themselves into very dangerous situations!

really? when i played through, the units under the commander where wiped out

Same, maybe they changed it. perhaps you "thought" the commander you killed corresponded to the units on that planet, but in actually it was a commander who built it, then left in an astreas. I think we'd need to have someone else confirm this, for the sake of consistancy. (having multiple results).