Mondor sizing across different models

[sampaguita]

I'm thinking of buying Mondor skate tights for winter (I'm moving in January -- temperature is in the 20-40F range). I'm a big fan of wearing skirts, and I hope I can keep doing so for the winter season.

I'm 4ft 10in tall, and almost at 100lbs. Mondor's size chart puts me in the 12-14 range, bordering on Adult Small. I have 3 pairs: footed 3310 and footless 3312 (Performance), and over-the-boot 3338 (Evolution), all in 12-14.

Here's the weird part: the 3338 fits me well, but the 3310/3312 don't. (The footless tights work if I put them over the boot, but if I don't, the seam of the back part can be seen because they end above the boot.) I'm wondering if this is because of a model issue, or a batch issue.

I prefer to get the Evolution tights as they just feel better overall. Do I go with 12-14 for footed/footless tights, or can I do with Adult Small? Thanks in advance!