Sorry to be an arse but the guy in the first video is food processing, not butchering. Ask him what parts he is removing and which are for sale to customer...
I go to a proper butcher for my meat. They take carcass ( pork, pig, lamb, chicken) and cut it in front of you and lay out all pieces (hearts, kidneys, gizzards) etc sell well here due to popularity of Masterchef and asians/other people who know how to slow cook food). They don't fuck it through a razor grinder and call themselves butchers.
Anyway... went to a Thai restaurant before and the chef would slice food with a fillet using metal spatula and jump it onto your plate. That was pretty skilled. I will cogitate the issue and come back with a good response.