I don't really trust the Beta but one idea I had for a first run would be a Beastmaster that focuses on Shifter damage with Stalker bonuses vis a vis ranger companion. Does anyone think this could be viable?

Disclaimer: I have not played Beta

 

But, one synergy I can think of is boar tusks triggering predator's sense in your pet.

Spiritshift Info: https://forums.obsidian.net/topic/96513-spiritshift-aggregated-info/

 

Ranger Classes: https://i.imgur.com/o6eC3wQ.png

Druid Classes: https://i.imgur.com/haPD50g.png

 

As mentioned above, if it's still available in Deadfire, Predator's Sense (Level 3) will be triggered by the Spiritshift Boar's attack. You also have Defensive Bond and Stalker's Link (Level 5).

 

Given that the base duration is 22 seconds per spiritshift though, you will possibly be using 2-3 forms per fight. In Pillars I usually went for Wolf as a Ranger pet, and had them engage just after my tank had collected aggro, picking off enemies from the edges. I'll probably keep similar tactics for Deadfire, so in this case I'd probably stick with Cat/Boar forms for the damage (maybe Boar first, then Cat and trigger Flurry).

As beta player: yes, totally viable.