I would eventually ditch thor and indo for better options. I would throw hp into indo g2 because of how defensive cautious strike is. Thylo is another option as one should really only boost its health and speed
The better a creature’s base HP, the better the increase with boosts. So for better improvements would be for Thyla, Thor or the Indos because they have to rely a lot on dodges.
Depending on how boosted in other things they are, I’d ditch Indo1 and Thor soon like Eduardo said. And I would increase the HP of Thyla or (argh) Indo2.
I’d say Indo G2. When the opponent can only do 1/6 of its normal damage, every boost brings it closer to immortality. It’s also the one dino I would be using in the very endgame–until it gets nerfed, of course. I don’t know how hard that nerf hammer’s going to hit, though, or how long it will be waiting. It took them a while to fix Dracoceratops, and even after its nerf, I still use it and it doesn’t feel like a weak link.