To make sure we’re talking a similar language: you have a castrated bull (steer) that has been grass-fed (free range reared) all its life?
Then you have high quality meat on the hoof!
Here, almost all our domestic beef is free range pasture (semi desert) fed, so the meat has less marbling (fat), is darker in colour and more gamier in flavour, and generally more nutritious than grain fed – high Omega 3, no antibiotics, etc.
Basically, the animal consumes what it was meant to naturally eat.
Wagu will obviously have more marbling because of genetics.
If your beast was raised and (eventually) slaughtered in a stress-free state, then the resultant meat should be perfect – a stressed animal produces lower quality meat, see Lactic Acid production, etc.
A quality Butcher is worth their weight in beef – if one tried to ground (mince) 50% of the meat here, there’d be a separate package containing 100% minced Butcher! In many instances, Butchers charge by the ‘cut’, so I’m guessing a lot of people want to save money and therefore gets a higher percentage minced.
If you’re VERY lucky, you may find a butcher that also knows Charcuterie.
The attached ‘Beef Cuts Poster’ should give you an indication, though it omits the head = jowls and tongue, and organ meat. Marinated beef tongue, tripe, steak (shin beef)and kidney
pie, stock (broth) made from the neck and bones, mmmmmmm!
So, there’s bugger-all that really needs to be ground – probably the round steak and the bits and pieces trimmed from elsewhere.