My experience of two-pilot light helo charters is that its driven by a complete absence of understanding of flight safety by the customer who demands it.
Some companies' policy requires their staff to be flown by two pilots and some indiciduals insist on it simply based on the false and unsubstantiated assumption that two must be safer than one. In all the flights I was involved in the 'other' pilot was a fully qualified line pilot just like the Captain but of course neither were trained or experienced in two-pilot ops, and on a couple of occasions there were CRM issues (one so serious that I declined to operate) that significantly compromised flight safety. Putting two single-pilot pilots together is a recipe for trouble and imho completely unacceptable. Include a non-pilot ground handler by all means, just not two one-man band pilots.
God knows I've seen the other side too, in airlines even after extensive CRM and human factors training many ex fast jet pilots (oddly never the Navy ones...) have been utter nightmares to fly with - persisting in being a one-man-band and refusing to include the copilot in a meaningful way.
By all means include a suitable ground handler - but never another single-pilot pilot.