Yeah, the Rating system can be a bit off. That Triceratops scores high due to it's near max HP/Max STR. Honestly though, i'd prefer a Triceratops with 85 Physical Resist over the near max HP/STR, since it's overcap in the most important Resist, and it can get STR up to 700 anyways, and the HP past 600 is basically just an extra buffer. Would prefer to take less damage in the first place (85 Phys) so that what HP he does have lasts longer and requires less healing.
I've had 2 slot Najasaurus appear as 113.4% Five Stars before in the calculations.