My feeling is that 'conventional' training is for pets.
LGDs are supposed to be working dogs for farms, not necessarily trained how to live in a peoplecentric society.
Yes, you do need some basic people oriented training such as 'come' 'stop' 'sit'.
The dogs need to recognize you as not just 'master', but as part of the pack.
Personally, I think that taking them to
city dog parks is counter productive to the end results desired for a farm work dog. This isn't about learning how to play with other dogs. This is about training them to chase off other dogs, rather than learning how to be everybody's buddy.
IMO, leash training is good for the occasional necessary trip to town (vet visit, etc.).
Actually, other than a vet visit, I'm having a hard time imagining any other reason to take him to town.
His sole job is guarding the livestock.
Leash training should be done AT HOME, on the farm. Take them for walks around the perimeter, to & fro' the
chicken coop, etc. Once they feel comfortable on leash, that emergency trip to the vet won't be nearly as traumatic.