Can Songs of The Wind Be Used to Summon Dragons?

[WhYdOyOuThInKtHaThApPeNeD]

You can get Royal Griffins from Song of the Wind? I used it many times with reload to see what all it could produce and the best I could get was regular griffins, and even those were very rare, Dryads also very rarely. Is there any trick to make RG's more likely with SotW? Being in some location, some continent, some specific area?

It seems like Song shows up more easily in early game than Colossus. It could be very nice to get some Dryads or RG's very early on.