Shimano Sora 3400 shifters with Shimano Alivio M430 rear derailleur? I'm thinking about a touring built with just spare parts I have.

I have a rear Alivio M430 9 speed derailleur and Alivio 9 speed 11-34t cassette already. I want to have drops and Sora 3400 is the cheapest 9 speed road shifters I could find. I don't think there is a difference between the cog spacing between road and MTB so it should work if my assumption is true.
Yes, with 9-speed this sort of combination works because Shimano mountain and road rear derailleur actuation was the same until mountain 10 came out.