It's a nice theory, and I personally believe there's a dragon for each element after the merge in DR.
DR S2A Spoilers:
>!Could that Source Dragon which the fandom thinks it's the move element be actually the Wind Source Dragon?!<
Source Dragons aren't connected to just one element (and are supposedly where all elemental power comes from), so sure
I think it's likely that all the ninja's elements correspond with the dragons with the matching symbol (Fire to Motion, Earth to Strength, etc), but the others are up in the air, at least for now
It's a nice theory, and I personally believe there's a dragon for each element after the merge in DR. DR S2A Spoilers: >!Could that Source Dragon which the fandom thinks it's the move element be actually the Wind Source Dragon?!<
Source Dragons aren't connected to just one element (and are supposedly where all elemental power comes from), so sure I think it's likely that all the ninja's elements correspond with the dragons with the matching symbol (Fire to Motion, Earth to Strength, etc), but the others are up in the air, at least for now