In any event, the fate of Mars' moons is already known to be sealed. Phobos the larger and nearer moon, is falling into Mars (orbital altitude is decreasing by 2 meters every 100 years), meaning it will break up and become a ring of detritus. Deimos, smaller and farther away, is slowly increasing its orbital altitude and will eventually escape Mars and fly away in Solar orbit.
So, like, who cares about speculating how they formed or were captured? Just wait long enough and it won't matter.
/s
I've often wondered if it would be more beneficial to crash both moons into Mars, or to boost Phobos up until it's stable, combine it with Deimos, and then thereby make Mar's rotation more stable.
But it seems to me the first step to fixing Mars is to get the solar wind to stop stripping atmosphere off of it. Either create a magnetic field on Mars, or put up a magnetic shield in the Lagrange point between Mars and the Sun.