Complex sentence: McQuitty and another director, John McClean, started a major change in policy, possibly trying to emulate other tea merchants that had also become successful retailers: they persuaded John Lane's brother Benjamin that the way ahead was to open Mazawattee retail shops.
Split into simpler sentences: McQuitty and another director, John McClean, whatever their motives, started a major change in policy, possibly trying to emulate other tea merchant firms that had also become successful retailers. They persuaded John Lane's brother Benjamin that the way ahead was to open Mazawattee retail shops.