Quite tempting to suggest a 3rd archetype, called Pack Dog, with general teamwork based abilities, which might include something like these 5 abilities:
- Dogpile (benefits to attacking/grappling an opponent whom an ally has already attacked/grappled),
- Dogpack (gain a bunch of doggy followers, scaling with level)
- Doggy Takedown (the trip ability previously suggested)
- Howl (general debuff, possibly with a buff to pack members)
- Alpha Dog (a bonus to all Best Friends or packmembers who can see or hear you).

A fourth archetype might be Guard Dog, with general aggro drawing abilities, even better perception and a more fearsome growl, perhaps better grappling etc.

And then there's Pit Dog, for a one-on-one scrapper.

However, I may be taking this all a bit too far, and lack the knowledge of 5E mechanics to execute it well.