While I think that your theory about Temp and flamescales and dragonet siblings, I also headcanon that it is rare for a dragon to born in the same egg as their sibling. Peril and Sky is a one in a hundred years type of thing. Even rarer is the fact that Peril sucked out Sky's flame. With SkyWings it is more common for the sibling in the egg to take their siblings flame because SkyWings don't really have anything else going on apart from their wings and their flame. SandWings and RainWings could take their siblings power, but I don't think that IceWings or SilkWings could take their siblings power, I think for IceWings the place that they already live in is so cold and they have their frostbreath in them, that if that they got any colder (taking their sibling's frostbreath) they would have health issues. And for SilkWings, if they had hyper-powered FlameSilk they would have problems with their wrists such as,like, blisters and such. I very glad there is a Wings of Fire podcast out there.
May the power of the Wings of fire be with you
Storm of the SeaWings
