Could this just be a backhanded way of saving the expense of two tanker fit outs? I'm reminded of the Navy's FFGs. The ship's ASW system was built around having ASW helos on board, which (for reasons that have been covered in depth here on other threads), never quite eventuated... So they stuck a ** utility Kiowa on the helideck as each new ship steamed in through Sydney Heads, reckoning (quite correctly) that the media and the great Australian unwashed wouldn't know the difference.