He's mobile for junior, but he's too slow to pull it off in the NHL. It's kind of similar to his passing, he makes good passes but they're very slow, I can see that being an issue as well. He has a decent shot and likes to pinch and get in close to the net so maybe that's why people consider him mobile? His first step is very slow, and he's poor at making breakout plays from his own end. He doesn't drive the play, but can make good reads to join in down low.
Dobson on the other hand is much more well rounded, he's a bit faster with an explosive first step and is much better at making breakout plays, whether quick turn around passing or taking it on his own.
Dobson drives the play, whereas Bouchard lets it develop and he'll pinch in later. Honestly its not close between the two, and Bouchard is being overrated pretty hard imo. The more I watch Dobson the more I think I'm underrating him. He's probably a safer pick than Hughes.