Air is a fuel source, I didn't say it was the only source. Which why if you suck out all the air from a room that's on fire, the fire will go out. Or some fire suppression systems use foam to smother the fire cutting it off from oxygen. It's also why backdraft is such a huge danger for firefighters. If you're cutting into a house that has a fire in it, it can explode into a huge fireball because it suddenly got access to more oxygen.
And yes, you're right, blowing out candles does snuff the fire, but that's more of stronger force suppressing a weaker one. If air/wind always snuffed out fire we would use wind cannons to fight fires.... also people blow on sparks or embers when trying to start a campfire or the like.
Rennaisance era alchemy which this is partially based on didn't have a concept of oxygen, but they did have observations and putting out fires using air/wind wasn't one of them.
And yes, you're right, blowing out candles does snuff the fire, but that's more of stronger force suppressing a weaker one. If air/wind always snuffed out fire we would use wind cannons to fight fires.... also people blow on sparks or embers when trying to start a campfire or the like.
Rennaisance era alchemy which this is partially based on didn't have a concept of oxygen, but they did have observations and putting out fires using air/wind wasn't one of them.