Betrayal Scarab of Reinforcements not working properly

The Betrayal Scarab of Reinforcements is not working properly. It is either a bug where the 50% doesnt stack with the atlas nodes. Or its just not working as it should.

Maybe the it should get changed to 100%, why would we rip a scarab slot for a maybe? I really feel like this scarab should get reworked or buffed.

Please look into this.