There is no fixed order or "batches" to them, except that if your last five special scans have contained no legends, and you still have at least one of the eligible legends left to catch, your next special scan is guaranteed to be one of those.
Legendary Zones (These zones always have the same layout every time, and will not contain any floating Poke Balls or missions to help score points toward the next scan)
Latios
Latias
Cobalion
Terrakion
Virizion
Keldeo (cannot be shiny)
Meloetta (cannot be shiny)
Battle Zones
Available in any type, with the same possible trainers as in 4-star zones but now boosted to level 200. Battle zones with multiple displayed types will take place on "large" maps, as with the large wild and battle zones seen at lower star levels.
Wild Zones
Normal - Porygon, Porygon2, and Porygon-Z
Normal - Eevee with Vaporeon, Jolteon, Espeon, and Umbreon
Normal - Eevee with Flareon, Leafeon, Glaceon, and Sylveon
Grass - starters (Bulbasaur, Treecko, and Chespin)
Fire - starters (Charmander, Torchic, and Fennekin)
Water - starters (Squirtle, Mudkip, and Froakie)
Electric - Rotom (in all of its available forms)
Rock - fossils (Amaura, Tyrunt, and Aerodactyl)
Poison - Galar Slowpoke, Hisui Qwilfish, and their evolutions
Ghost - Gimmighoul (Chest form only; these have a higher level when caught than the Pokemon in other wild zones)
Ice - Frigibax, Bergmite, and Hisui Avalugg
Dragon - Frigibax, Hisui Sliggoo, and Hisui Goodra
