Is a flat coat black retreiver and a german shepherd a bad idea?

We are looking for another doggo, and the shelter has this sweet boy who is 3 , 110 lbs, and a golden retriever/German shepherd mix. He's pretty calm and gets along with our dog. When he does pull he's very strong though. He was also malnourished for his first couple years as previous owners couldn't afford vet bills etc..but he is good now.

I am wondering though, it seems like a bad combo. He's real tall and gangly. Not that we can't afford medical bills for him, I'm just concerned...he also has anxiety but I think a stable house would help him.

We figured if someone doesn't adopt him in a week we would maybe get him.