So cheking some damage table son the wiki, i came to the conclusion that it's better to leave all your swords at 4* (the damage differences are of no more than 20 points) and upgrade them later, but first get a krogmo trinket. With the bonus trinket, you'd get even more damage on all weapons at once instead of needing to upgrade them one by one. This may make an impact on some upgrade plans.
Is this true? (to non Skolver + BTS users of course)