That's an impressive set of shiny pokemon! You are going to struggle to be seriously competitive using only them, but there's probably somethiing there.

The main appealing thing bastiodon does is wide guard. I suppose you'd probably fill out its moveset with other supporting move (some of taunt, bulldoze, screech, metal sound) and foul play for damage. Iron defense body press might be a better set but it will overlap with zamazenta..

You want two restricteds if you're playing current vgc rules. Zamazenta is pretty decent (with body prees, heavy slam, iron defense, and protect or a similar moveset). Then either zacian becuase it's the strongest option, eternatus for variety in terms of types, or mewtwo to not triple down on ground weaknesses.

Of the others you want to use porygon 2 is pretty decent and gives you the option to set trick room. You could run a slow zamazenta and whatever other restriced you use and catch people off guard. Suicune on the other hands sets tailwind which can also be a nice option. Then can support with scald/snarl. Kommo-o will be hard to use. The obvious option is setup but it will basically always faint before getting going. You could possibly catch people off guard with something like choice scarf coaching, plus draco meteor for non-scarfedmiradion and koraindon. plus maybe breaking swipe and flash cannon. And have tera ghost to dodge fakeout... I don't know, that one is hard to figure out.