You can thank Blizzard for that. As much as I dislike Tyrande, the main difference between her and other faction leaders is having too many writers having their way with her and using her to prop up others.
Anduin is only winning anything due to the Soviet strategy of throwing bodies at the Horde. He has regularly been outplayed and outmaneuvered by both Sylvanas and Saurfang at the tactical level. If Blizzard cared for having competent generals, Turalyon would be the military leader of the Alliance, seeing has he’s had it before.