Upvote:1
Theoretically, any combination is possible, but realistically, most of the time the airline that executes the first leg of the trip defines the luggage rules - that means weight and size allowance as well as cost. That means it won't matter through which airline you book your ticket. One reason is that they have to physically handle the luggage check-in - plus they probably find it as complicated as most other users to understand all the details from the following partner airlines - imagine, if they are in sky-xxx-group with 12 global partner airlines, they would need to fully know all baggage rules and cost from all them.
Worst case would be that the worst (smallest, lightest, and most expensive) combination is valid, as each airline only wants to transport luggage according to their own rules. In reality though, most major groups have agreed to respect the first-leg-airlines rules.
So yes, you're stuck with paying Austria however much they ask.