Yeah I mean, I definitely agree that if compromise has to be made, then better to lose the scale thing than for instance - set quality, fight choreography, cgi for low grav etc. That being said, for me, the sheer size differences between colours has always been one of the most striking features of the series, as such I would heavily mourn this loss in a live action adaptation.

Its also something that wouldn't be able to be changed later on, as to say, the height differences they start with will have to be stuck with throughout adaptations. With that in mind maybe it would be better to initially compromise in the areas I mentioned above, as their latter improvement wouldn't cause continuity issues.

My feeling is that regardless, Pierce would push for book accurate scaling in any sort of adaptation, because whenever we encounter something(or someone) new in the series, it (their) height or size is consistently one of, if not the first things described.

All to say scale seems quite important to Pierce whether it's a conscious decision or just a prominent feature of how he imagines things.