ok so 2 hours of reading this thread & 2 cups of cocoa downed & STILL I've seen nothing about 4 specific tames so here we go.
Rhino currently only gathers metal from pure metal & ignores common metal sources from stones that provide a Stone, Flint, & Metal type, I'm sure I don't need to say how stupid this is as I'm sure lots of you have come across an island with oh lets say copper but no pure metal nodes so your Rhino is useless as a metal harvester on this island type. I find this incredibly vexing and have come up with a simple rate 1 to 10/10 so for every Stone & flint gathered a Rhino should also gather one metal so when striking a common rock Rhino Gathers 100 Stone, 100 Flint, & 20 Metal this makes Rhino better for all metals not just the pure metal nodes.
Shieldhorn, Razortooth, Leatherwing: these NEED to be tamable on ALL Powerstone islands NOT JUST on the Turquoise stones island.
I hope lots of people see & agree how stupid the Rhino's gathering & the taming limitation is on the 3 Current Dinosaurs.