Finished Far Cry Primal, but the play through is only at 54.02%

I just finished Far Cry Primal. I played about 30 hours, and did all the (people) missions. I also build and crafted everything. I conquered all the towers and area's, and tamed all the beasts.

The only thing I didn't do is collected all the 'hands' and jewelry. And also not all of the red side missions.

During the game I was wondering about how big the game was, but since it now ended with 54% playthrough I'm a bit confused. Since I think I played it through for about 80-90%

I can't basically believe that those red missions and those collections of hands and jewelry (which I collected about 20%) would be more than half of the game.

Any idea?

I found this on another site

Have you crafted all craftables, upgraded all skills, collected all collectibles and completed all missions? Have you uncovered all unknown locations (black ? on the map)? Have you killed and tamed each type of animal?

If you go into Takkar's cave, the stone in the middle displays game progress with the percentage. On the right-hand side it should list your progress in each category. Check that. In fact, check every one in that cave and see if any aren't complete. Should give you your answer.