I have both 17/18 and 18/19.I do not understand "Not all the same"?
But yes, it must be quite a lot difference between the cars, however it seems that you are one of the lucky guys, good for you. If you run 17/18" thats a big difference/advantage as well. Unfortunately, 18/19" combo is how mine was delivered, even my trackday 17/18" semi slicks are more comfortable than OEM 18/19".
So for us not so lucky guys, 2x15mm spacer is worth testing out to resolve tramlining. Honesty, I've been wondering about removing AW blocks(decrease caster) and see how OEM with rear spacer works, might be perfect for me.