Warrior has 2 very straight forward combos. They are run of the mill 1,2, 3 combos, with each combo doing a specific thing.

1. Hate generator combo.
2. Damage mitigation combo/DPS increase combo.

#2 combo shares the firsr two skills, with the 3rd skill being different depending on either applying Damage mitigation or DPSincrease. You can easily fit this combo on one cross hotbar.

#1 combo is only really used while you're Main tanking and once hate is established, it's all #2 until you need to increase your hate.