How far is a 50 range increase?

It helps a lot with Bodyguard A, except FA doesn't apply to the range increase.
Good thing Majestic Presence will for Corsairs

Except you don't need it as a bow master to bodyguard successfully.

Also, Mercedes shoot further than bowmasters with the Ishtars Ring upgrade, noticeable places are Horntail's cave when you stand on the platform by the right hand. Then you attack the left hand from that right hand side. Hurricane can't do that but isthar's Extended range can.