Arceus, Dialga, Palkia and Giratina vs Z

That's from Pokemon Diamond Pokedex:

"It is described in mythology as the Pokemon that shaped the universe with its 1,000 arms."
Seems to be just a figure of speech, since Arceus can't even learn arm moves like ThunderPunch, Fire Punch, etc.

Pearl Dex:
"It is told in mythology that this Pokémon was born before the universe even existed."

Platinum Dex:
"It is said to have emerged from an egg in a place where there was nothing, then shaped the world."

So wait it can't even learn certain techniques? Yet it created the beings that use those techniques?

I think the game versions would have a better chance IMO. Dialga and Palkia are stated to be the avatars of space and time, and with their compine powers into one they where able to end the universe IIRC. Arceus is superior to Dialga and Palkia, their combined might is equal to cube level beings.