With no kinetic resists, it's just as easy and better to get a plain vanilla Rancor provided you can handle the extra 4 levels of difficulty. The regular Rancor has better specials too
I tamed one today on 3rd try their not much of a challenge to get at all. Couple friends and I were getting normal "Rancor Lair" missions and a Gnarled baby came outta the first one. We did them outta the Science Outpost on Dathomir