The Operator, Client, and CAA have that responsibility. Pilots operate within the the confines of the Law, Regulations, Rules, SOP's, and Approved Procedures, and Contract Terms.
If the Big Three have approved the carriage of those you think too large for their own good...it is not your remit to make that judgement. Raise the issue in a Safety Meeting, make your views known, and stick to doing your job until the Rules change.
The US EMS industry....the cheap outfits that use Jet Rangers....love skinny Pilots as the very limited Payload demands Pilots who suffer from Anorexia in order to get off the ground with a patient.
Fortunately for the Offshore Industry the Client pays by the Hour and by the Pound.....not by the number of passengers.