I think the Houston team total is taking into account they likely only bat 8 times since they'll most likely be winning and not need to hit in the 9th. I still think the over has a bit of value though, they can easily score 5 runs in one inning, let alone 8 innings.
I played the Yankees here. Feel a bit dirty paying any juice on Sonny Gray, but he's actually been a bit better lately and I think teams that win the first half of a double header (they finished a previously started game) tend to have a bit of a letdown in game 2. Nats won the first game, gonna fade them in game 2. Just 1u though.