Benson’s final designs are greatly simplified from the base version and this is down to aid his continuity and recognisability. I also felt the character needed particular features that link him to the Baron without necessarily being ‘equal’ in social status. as a result, the back of his waistcoat has the same stripes as the Barons shirt. also as a further enforcement of the Barons influence, he insists that Benson (and any of his underlings) paints a red diamond around their left eye in homage to his own eyepatch. This acts as a symbol of loyalty and support of the Red Baron.
The final troll design takes some influence from the Magicville minions’ use of masks. The trolls seem to be naturally magical creatures. That is to say they have misterious cultural traits such as wearing enchanted masks that move and show expression. Presumably, this is to hide something much less friendly beneath from other beings that live in the kingdom.