Tie length, should you adjust it to your trousers, or to your body?

We've all heard the rule about letting the tie reach the middle or top of your belt buckle, and if you follow this rule when wearing pants with a "normal" rise you'll be pretty safe, but how should this be adapted when wearing higher rising trousers?

Should the tie length be determined by the top of your trousers, or should it be determined by the length of your torso where the top of your trousers functions as a proxy? If a certain tie length looks good and hits the top with average rising trousers, should this be kept for high-rising trousers as it's a good length for your torso, or should it shortened to reach the top of the high rising trousers?

Right, that's fair enough, and if your trousers aren't extremely low or extremely high rising (or you have very strange proportions), that's probably going to make the ties hang exactly as they should.

However, if you for some reason started wearing much more high-rising trousers tomorrow, would you keep your current tie length that presumably suits the length/size of your torso and legs, or would you start buying much shorter ties so that any new tie you bought would conform to the beltbuckle rule for the high rising trousers?

This is the situation I'm in now you see, and trying to make up my mind about it.

I'm sure he could, the question is if he should...

I don't know, I just feel that it still looks right to have the same tie length with high trousers as I would with medium as they look well proportioned to my body and to the length of the jacket, and I suspect if I had them shorter I'd be observing the rule, but that the effect would be a less elegant impression as a whole.
However, I'm not sure if I've really decided on that or if it's more like a passing fancy, so I was wondering if anyone else has made a similar observation.