If in the end, you find that your tires are not the problem and the front and rear wheel sets are each aligned correctly, then it is possible that the thrust alignment needs adjustment. That is the alignment of the rear wheels relative to the front wheels (or vice-versa). I can’t explain how the vehicle drove well with your old tires unless you got an alignment along with the new tires that caused a thrust alignment issue or revealed a thrust misalignment that was masking another problem such as unequal front wheel caster. Unequal front wheel caster has a profound effect on steering pull but will not cause undue tire wear.