Yes, and *4 can use for event challange both in Epic and Legendary limitation. And also use for tournamnent, etc.
IMO, ascend order priority:
Red: WIlbur (ascend), BT (ascend), finish Scarlett, Sir Lancelot and Colen to 3.60, (Anzogh) or wait other red. Scarlett is very high attack tile.
Blue: finish Magni 3.70, finish Boril to 3.60, finish 1&2 Thorne to 2.60
(wait for Kiril, Sonya and Grimm, and switch after you get one of those 3 key blue heroes)
Green: Hansel (ascend), Melendor (ascend), Caedmon (ascend), finish Skittleskull to 3.60, finish Kashshrek to 3.60.
Yellow: you have already maxed Wu Kong, so Ranvir can wait, you do not have any maxed *4 yellow, Wu Kong only for Titan, so ascend Chao and Hu Tao.
Purple: Merlin (ascend), finish Ameonna to 3.60 (good for offense), finish Jabbar to 3.60, finish Sartana to 3.70, finish Obakan to 2.60.