Resists are almost entirely useless to weight in the new system. Resists are cheap to train compared to hits / STR.
High HITS and STR is what to look for.
Resists have the same value as a point of str or hits in animal training, x3.0. They are equally as important as I will explain:
On something like a prepatch dragon, I will take str out of the equation for my example as str is untrainable, but yes, when looking at a dragon, you want high str due to the fact it's untrainable. (For the record dragon str variance is 29 or 87 animal training points worth.
Dragon hits only have a natural variance of 17 points, or 51 training points.
Dragon resists have a variance of 10 points per resist or 150 training points.
Prepatch nightmares:
Str variance of 29, 87 training points.
Hits variance of 17, 51 training points.
Resist variance 50, 150 training points.
You want to weigh all the when looking at an animal. A cruddy resist roll on some animals can end up costing hundreds of training points.
And no I would not use a pet calculator for legacys, I would use their total imbue value (with str top priority on wyrms and dragons)