Dobson. By a lot.
Bouchard is great offensively but still makes way to many gaffes defensively whereas Dobson is one of those rare all round guys that you can build a D around.
Is Bouchard really that good offensively though? He does have a hard shot, but he hits quite a few shins and doesn't seem to get shots on net as often as you'd think. He does have an excellent outlet pass, but he isn't able to skate the puck out of his zone and through the neutral zone so he's a bit of a one trick pony in that respect. I just don't see this dynamic offensive force that so many others describe. He is a very good passer and bomb of a shot, but not seeing much more to be considered "great offensively".
Dobson can skate the puck up the ice and make the outlet pass, his offensive game seems way more diverse and "dynamic" in comparison. He does a very nice job getting shots on net, sneaky good.
While both are not defensive stalwarts, Dobson has made strides in that area while Bouchard still makes Junior level mistakes. Bouchard looks like he doesn't give a shit about playing defense, that's not good.