Yes. Considering his facial characteristic and height, he could play Engineer.
And yes... that dog tag belonged to someone from Covenant crew.
I m completely sure. Maybe it belonged to Demian Bichir's character!
One new thing...
Remember how someone who claimed to have seen the move (I think Sagardoa)
said that the person standing next to Daniels on photo below is Bichir's character...
When asked about the name he said he forgot it... as any other name for that matter.
Well let me tell you, that is not Bichir's character!!! And its obvious from the trailer!