Update Jan 20
A full datamined table of all the new Pokémon stats has been linked by Centro LEAKS. This tables all the sats of the 28 new Pokémon coming to Pokémon Legends: Arceus, along with abilities and EV's. The stat table can be found here.
Since fans have gotten access to the complete Pokémon Legends: Arceus Switch title, leaks have been plentiful, and more keep emerging online. The main focus of these leaks has been the new Pokémon appearing, and they have discovered the stats of all these new species in the game.
According to this newly leaked information, there are 28 new Pokémon appearing in Pokémon Legends: Arceus and Reddit user Jugol have shared all the stats and details to the PokeLeaks Reddit for all to see. And Pokeplayers are already analyzing these details and comparing them to their base counterparts/pre-evolutions.
Related: Abilities revealed for New Pokémon in Pokémon Legends: Arceus leak
Jugol does mention in their post that the stat order has been changed once before, and they are using the general format for previous titles in the series, yet there is no way of knowing the correct order until the game is released, so don't take it as face value.
Remember, there is no way to confirm the authenticity and accuracy of this information, as the game is not yet available to play.
Pokémon Legends: Arceus is releasing on Jan. 28 for the Nintendo Switch.
For more on Pokémon Legends: Arceus, Pro Game Guides has you covered.