the phrase "more accurate" is an oxymoron. all speakers are inaccurate. accuracy is dichotomous. there is a state of accuracy and a state of inaccuracy.
one can use the phrase less inaccurate to indicate a state which is closer to accurate, i.e., perfection.
as has already been said it is difficult to quantify inaccuracy. it is possibly to provide measurements of various parameters. then what ? how do you quantify accuracy, given measurement statistics ?
why not consider which speakers are most resolving, if that is your goal ?