Equipment as you're leveling up tends to alternate between different secondary stats, so for instance one set may have a Crit bonus and the next an Accuracy bonus, or more Det. But if the damage (weapon) or Defense (armour) goes up, or if your primary stat (DEX in the case of Archer/Bard) goes up, then it's an improvement over the previous item. Only where the Damage/Defense stats and the DEX bonus are the same would you choose an item based on those secondary stats.

Sometimes you'll get a case where a High Quality version of equipment at one tier has similar stats as the Normal Quality item of the next tier up. Or you might get two Aetherial versions of the same item that have the same main stats but boost different secondary ones. In those cases you can choose based on secondary stats. It's also a consideration if you're going to add materia to an item and need to decide which type to add. But for the most part, you can consider those secondary stats more as a tiebreaker when all else is equal.