If i'm not wrong, the place can burn 3 times during the day, first one at Server save, second one 8 hours after Server save, and the next one 16 hours after that.
I guess you can make 6 thornfire wolves appear when the town is fully on fire, so that gives you up to 18 wolves during a day.
Remember that there's a trick to get both thornfire and crystal wolf out of 1 to get charm points, that gives you a lot of chances of getting the full 100 points in just one day.