I can't believe I have to repeat myself yet again but here we go.I understand what you are saying they need to clear the boat No1 so that boat C can be lowered. But letting the cutter boat sail away with so few on board. I am afraid Smith should made clear the boat should of stayed around to pick up more passengers. Much can be said for the same for other boats leaving half empty to. Smith knows there not enough boats to take all.
If they had kept Boat No. One any longer then there would not have been enough time to get away Collapsible C. They would have had to float C off the deck as a consequence which would have been hazardous and cost lives.
Keeping No. One around means denying Murdoch, Lowe and their AB's attention at other boats. They could not afford to hang around.
There is also doubt whether the two cutters really could have safely held forty adults. Twenty maximum is much more realistic.
Murdoch was entirely correct decision to clear No. One away when he did.