Well, I just had the thought that if the killers were from out of the country, and were leaving by airplane, they could not carry guns, because of metal detectors, so they would have to get rid of them, even it they were supplied to them here. It is just one more thing that could provide bullets, and other evidence that could be traced, so maybe it was much better for them to use neck compression as a method of killing, and I suspect that as professionals, they had been trained very well in how to do it quickly, and efficiently.
It also seems to me that they were ordered to display the bodies hanging. It is possible that someone wanted Barry to see Honey hanging as the last thing he saw, horrible as that sounds. Imagine the horror, if he was forced to walk into that pool room, by being strong-armed by one or two men who had just pulled his coat down, quickly zip-tied his wrists behind him, and maybe were holding a knife on him. Someone really wanted them to suffer just before they died in great fear, if that is the case. I think they also wanted to send a message to some others, possibly including the Sherman children, that this could happen to them. Just what the Shermans did to cause such wrath, I am not sure, but there definitely was an extremely intimidating message being sent in their method, and manner of death. IMO