Does Tribal Fury splash and Cultist Greathammer splash effect each other?

Im new to the game and am not sure if I'm testing this right in-game. I wanted to see if the 1.5 meter splash dmg on strikes from Tribal Fury in the passive tree added onto the innate 1.5 meter splash dmg that comes with Cultist greathammers and the Unique "Empty Roar" to make a 3 meter splash dmg. After spec'ing into that passive I can't tell if the aoe on strikes is larger and theres no feedback in the skills page when i open up my strike's information. Maybe it just applies splash damage twice in the same 1.5 meter radius instead of making a 3 meter area? I can't tell, any help would be appreciated.