Combo caps at 28 per shot and with 2 combo per pellet that means you only need 70% multishot. We're way above that with galv.
Using [Sweeping Serration] to make the primary damage slash again. 26.4 multishot with 28.8% status we should be applying 3 status per shot, assuming everything hits.
The vigilant combo i find uniquely funny for this weapon. I hope you like math.
Probability A = Base crit chance
Probability B = Vigilant Set
The probability of either A or B happening is 14.8%. So you have 14.8% chance to crit. This is a 146.66% critical chance increase.