I got the Pim ending where the Principi become a transit company by siding with the Huana and killing both Furrante and Aeldys. I spared Benweth so that Aeldys was imprisoned in Dunnage, killed Furrante and his captains when he asked me to interrogate Aeldys and then set her free. I then manually attacked her (which also turned Mad Morena hostile, but not Pim) and killed the two of them, leaving only Pim alive who was still neutral. This ended the Principi questline for me, but since I was siding with the Huana it all worked out.
According to https://pillarsofeternity.gamepedia.com/Pillars_of_Eternity_II:_Deadfire_endings it looks like that's only a possibility with the Huana claiming Ukaizo.