I think the # of win required to capture territories was lowered from 20 to 15 recently ... it took a long time to go from 70 to 50 territories remaining, but not so long to go from 50 to 15.
It has been capped at 15 since the beginning of this season, in an effort to make this season shorter than last time.
I think that a lot of the lower ranked clans all finally got enough wins (they get 1 win every few days) to get a next terr.