Hey man, I am a mechanical engineer. Mechanical engineering is indeed very broad, in fact the broadest from all the engineering disciplines. Usually the aero classes that you are interested in, you might be able to chose them from a mechanical engineering degree, doing an aero concentration if you may. From my experience Aero and Mech students do target similar jobs and you might have a slight advantage or disadvantage over the others, but it all comes down to your personality and competencies! I would suggest that you choose a degree where you can switch after year 2 ( I know that Leeds allows you to do that), as the first 2 years are similar. Or look into a General Engineering degree, where you can specialize in what you won't to do. The decision is your alone, but I believe that you will not have major issues in finding your desired job in the future, with any of the two. Make sure you look carefully into what modules every Uni offers and that you can chose the ones you want!