Without being able to confirm, I'd suppose with racquets featuring the same drill pattern but different static weight only, it is very likely you can lead up the lighter version to the same specs as the heavier one, thus essentially treating it like a "pro stock" (famous words!) version. Will it "feel" the same? Probably not. Better? Worse? -> Just slightly different, and whatever you prefer only you can say.
I think Fischer did definitely do this back when they were still in business. They had multiple weight options of the same stick and they only ever added weight in the handle. Note that for the same stick, the lighter version will invariably be less head-light so that weight is basically only added to the handle!
Also, from an economic point of view, this practice makes much more sense than having racquets with different weights also differing with regard to layup (given that the drill pattern is the same, of course). Exceptions to this may exist - for instance, I think (!) Head's YTIG Prestige Pro and MP didn't just differ in drill/string pattern and weight. But again, my best bet would be that most companies offering the same stick in different weights just add cheap stuff to the handle for achieving heavier versions.
Also, different RA readings probably are just a consequence of having more weight in the handle, too. BUT: I've never used an RDC myself nor given too much emphasis on a figure such as the RA, anyway. There are some users here who know a great deal about that stuff, though.
And: All of this would be valid for retail sticks only, of course.