The bullpen right now is not versatile. You have Tate and Scott to mix and match with in the late innings, Valdez to close, and basically four longmen/mopup guys that you ideally want to hand a clean inning to. That leaves Armstrong. There's just no good option when it's only the fifth inning but it's high leverage.
Should Hyde have planned for this? Maybe. We know that Lopez is not effective when hitters see him for the third time. With that in mind I don't think he should have faced Judge and maybe not even LeMahieu. Putting in Armstrong with two out and and only one on at least gives him room to nibble while he feels his way back. People are saying you have to let Lopez "learn" to escape his own messes as if he's a young guy who projects as a frontline starter, but I think he kinda is what he is and you be content with 4 2/3 IP out of him.