Unfortunately reading CruzFo's post the reality of these contract's can often be seen.
You sign a contract with a Contractor who is based in one Country, Maybe your own which is better. You agree to be based in another Country
with A hirer, The Airline.
You are working for the Hirer in another Country. The hirer know's this and can change or try to change what you signed with the contractor.
The Contractor probably has no real power in the other Country you are working.
The Main thing is can you go after the Contractor if there is a problem which is not what you agreed with them. Probably yes but are you willing to spend the Money to do that? Probably They know all this as well.