Spent the last hour gearing up, went out and tamed a heal pig. Brought him back to base and even found a saddle, bright happy feelings!!! for a min..
...sigh...
Plopped him down next to the rexes and cautiously threw a row and a half of raw in his inventory and force fed him about twenty meat, feeding trough nearby too... found the setting "enable passive healing" in the pop up wheel. Set that and went away for a few min. Came back and looked in the rexes inventory, no noticeable change in hp... thought "okay maybe it's just a trickle of healing that i'm going to not notice with out a stop watch," set a stop watch, no change (beyond the ~500 per 8min), hopped on the pig and right clicked on a whim, some words popped up and I think like a green wave went out or something and it was like... allegedly healing nearby guys or somethin, checked rexes inventory's and still no change! Twiddled my thumbs, tried a few other things, got mad and podded everything up.