It has been a while since I had Mollies of any type in my aquarium, but I can testify to the Resilience of the Cory Cats. I have had cory's and they outlive everything. Seems to me that if I remembe correctly that the mollies actually licked to have some salt in their water, ie brackish. Don't know if this helps.

Its not how well you do something,
Its how well you look doing it!