He's not starting at any other spot barring injury. So I'm not sure what your point is. Pujols starts at 1B. Morales is your best DH. So it's either 3B or off the bench. He's a solid option at either of those spots.
I'm not making any arguments that Trumbo is in all-star. He is simply a guy who hit 29 HRs his rookie year. That's a nice option to have on your team to either upgrade 3B production and hit in the back half of your order, or bring off the bench to give guys a night off or fill in for injury.