1) It's an industrialized planet with a large population, economically that's a big boost.
2) IIRC, Mandalore's martial culture is pretty ingrained. Even if the Pacifist movement got most people to put away their blasters, and they don't have much of a standing army, they probably have a sizable number of experienced combatants that could be mobilized.
But mostly it's Star Wars and things don't make that much sense.
RE: Mandalorian Pacifism,
Somebody correct me if I'm wrong, but IIRC (and checking Wookiepedia)
There was the "New Mandalorian Movement", which was an anti-militaristic reform movement, but not strictly Pacifist, just seeking to move Mandalore away from it's traditional martial culture. When Satine became Duchess, she aligned her government with the New Mandalorians.
This led to a brutal civil war, which the reformists won. However, witnessing the death and violence of that conflict turned Satine into a Pacifist, which was a step beyond the New Mandalorians.
So, Satine was a pacifist, but many people in her government (And the people who fought the civil war on her behalf) were probably not Pacifists, and may have bridled as Satine went beyond "We should stop glorifying warfare" to "Violence is always bad and we must reject it in all it's forms".
By "Exiled the Warriors", they seem to be referring to the losing side in the civil war, rather than "Everybody who can fight". The people who refused to get in line behind the New Mandalorian reforms.