At present, I am working under the belief that there are 5 town, 2 mafia.

Worst case scenario:
Nyx town, Tyche town, can't prevent own lynch.

3 town, 2 mafia.
Mafia or Hebe kills town tonight; Hestia's protection misses targets, my own little ability does not pay off.

So yes, they can win, but they need a smurfload to go right for them.