Hi. In this case rating them both with and without the checkbox is valid. Pets are now locked into their starting slot upon spawning, so you don't have to worry about them slot jumping with too much intensity (other than a few select pets, like Legacy Dragons and Windrunners/Skeletal Cats). Without the checkbox is how your pet rates in its current state at the time of taming. If you check the checkbox, it makes the assumption that you will skill your pet to 125 natural stats for free before starting training, which is why the rating jumps to a 3 slot (basically if it had those stats at the time of spawning, it would have tamed as a 3 slot).
The reason you get the borderline pet when you set dex to 0 is because it is bumping that up to 125 (with the checkbox) instead of using the pet's actual minimum rating (we don't enforce the database min/max ratings in the event you find a pet outside those bounds). That combined with the lower intensity from 100 resisting spells put it in what I call the "borderline threshold", which is what you see when it lists an intensity for both slot possibilities (if you click on the triangle information sign, it will give an information page on this).
The % rating you get is based on that slot-level. So 94.8% is based on a possible 2-slot najasaurus. This why the rating gets very low once the intensity gets bumped to a 3-slot pet. (There is a bug I do notice in the detailed display though, it shows 5014 as the possible intensity cap, however that is the possible intensity cap of a 3-slot najasaurus -- it should show the intensity cap for the slot level it is comparing against, in this case a 2-slot. I can fix this in a future update. The % rating is accurate for that slot-level though).
To directly answer you original question though, you should uncheck the box if you are rating a pet that can spawn as multi-slot to get the more accurate rating.
100% pets are pretty much only possible on multi-slot pets due to the intensity range available to them. It is much more probable for them to roll stats that put them at the high-end of a 2-slot vs a pet that only spawns in a single control slot range, which would need to roll every stat perfectly.
There is a wide range of inaccurate information out there on the common mob wikis. We try to validate all information personally with in-game tests the best we can (we tamed/lored probably close to 100 Ossein Rams and never saw over 290). You can always send me or
@Khaelor a PM with the lore page of any pets you find outside the spectrum and we can adjust the database as needed.
If you were to find a perfectly rolled Ossein Ram it would still rate as a 2-slot pet in the calculator, it would just show as over 100%:
Pet Intensity Calculator | uo-cah.com
