is the apostrophe after renunciants required?

[Guest guest]

>In response to cavils against Vaisnava renunciants' adopting

>different dress than that of the Six Gosvamis,

>

>(I think it isn't required, but my editor insists we check with the

>Editing conf pandits)

 

The apostrophe should be there.

 

(You'd say, "against their adopting.")

 

By the way: Idiom calls for "different from," not "different than."

 

(". . . adopting a dress different from that of. . . ")