Theory: The Galarian Legendary Birds aren't Actually Regional Forms

Earlier today, I was messing around with the Legendary Birds using the Synchro Machine, and a thought popped into my head. What if the Galarian Legendary Birds were actually separate species? It may seem a little bit odd at first, but hear me out:

They don't have very much in common

They do have similar appearances, and they primarily inflict the same status conditions, but besides that, they're pretty different. While regional forms can be this way, "regional fakes", such as how Wiglett is to Diglett, are also like this.

Their Pokédex entries deviate from the usual

The Pokédex entries for the Galarian Legendary Birds don't describe how the Pokémon became that way. Instead, they describe how the Pokémon got its name. It could potentially imply that the Pokémon having the same name is a coincidence, or maybe they were named after the Kantonian Legendary Birds.

They resemble completely different species of birds

This more apparently applies to Zapdos and Moltres, but to some extent, it applies to Articuno. Articuno has some magpie- and quetzal- like aspects to its design, and while the Galarian form keeps that, the move Freezing Glare also brings to mind the mythical Cockatrice, said to petrify with a glare. Zapdos resembles a hummingbird, meanwhile Galarian Zapdos features aspects pertaining to ratites (kiwis, ostriches, etc.) and roadrunners. Finally, Moltres appears to be based on a heron, but Galarian Moltres's beak, having a bit of a hook at the end, and its bulkier neck more closely resemble a cormorant. Other regional forms (if based on a real animal) seem to be based on a different variety of the same species, or at least a closely related one.

Mistakes in classification can happen

In real life, there are some things that share a name despite not being related at all. For example, the American robin is not a true robin, instead being a thrush. People called it that because the orange feathers reminded them of the true robins from the Old World. In reality, they're classified very differently, with them only sharing up to their order, Passeriformes. For reference, a thrush is as close to a robin as a dog is to a bear, walrus, or weasel. As for why they share a Pokédex number, it could be that the person developing the Pokédex didn't know they were separate species. There have been some cases where multiple different species were thought to be different morphs of one species. Giraffes were once classified as one species with different pattern variations. For example, some giraffes have more polygonal spots, while others have irregular shapes. However, it turned out that they were each different species.

Honorable mention

The official Pokémon Sword and Shield website states that "For a long time, [Galarian Articuno] was thought to be the same Legendary Pokémon as the Articuno previously discovered in other regions", and the equivalent for the other two Legendary Birds. This can either imply that they weren't even believed to be a regional form, or they aren't technically the same species.

Conclusion

The Galarian Legendary Birds heavily resemble the Kantonian Legendary Birds, but we've seen other Pokémon that resemble preexisting Pokémon without being related. They differ from most regional forms in several ways, and most official sources don't say that they are the Legendary Birds, but rather imply that they aren't. Was I overthinking this whole thing? Probably. Is anybody going to bother to read this? I don't know. I just thought it would be good to share it and see what other people think!