further is a different type of maths compared to methods and spesh. I would consider myself a maths person (doing all three maths) but I quite dislike further, there is a lot of data interpretation, finance, stats etc, reminds me a lot of stuff I did commerce and health; very different from the calculus and trig in methods and spesh. I suggest you do methods early if your school allows, it will help drastically if you continue to do spesh 3/4 in year 12 after completing methods. But if you can't do that, definitely at least try doing methods and spesh in year 11, see if you like the content and you can always drop spesh for further in year 12. Generally, if you are good at methods, you would also be good in spesh, given that you can properly manage your time. Hope that helps!