It’s as radar said
Ninja family bonus stacks with the status effect. The status effects are broken into two sets:
Kafilen Costume & Inari do NOT stack with each other but override / replace
Margaret & Costume Little John do NOT stack with each other.
However, the two sets do stack with each other. I.e. Inari will stack with Margaret.
Not sure how they stack mathematically;
It could be multiplicative or it may be that they process separately (i.e. chance of one, if it fails then it processes the chance for the second).
Can’t confirm one way or the other; but the bottom line is that “yes, having both you’re more likely to succeed in dodging”.