Yes. At least "primarily". Lineups are fluid and sometimes a player will DH to get a bit of a break, But think of it this way: if the goal is to essentially have Ballesteros as your main DH against RHP, but you don't want him to start against LHP, then Shaw is Ballesteros. replacement.
If you don't really want Shaw hitting against RHP as the game goes on, but you have him at 3b over Bregman and Bregman at DH you're in a bad spot. You can't move Bregman to 3b, or you'd lose the DH. So then you either are forced into Matt Shaw hitting against a tough RHP, or substituting your best LHH - none of which play 3b. If this spot comes up in the 6th, and you PH Shaw for Ballesteros, Mo gets one PA, and then you have to insert Scott Kingery the rest of the game. That's it. That's all you got.