No, it only refers to the status of
clusters. It tells us nothing about individual constituents of the cluster.
Well, take the Dale and Krueger paper you mentioned (
here). It is talking about US higher education and consequent employment. It is not talking about the UK, which has a significantly different higher education culture. Your whole approach, I feel, is back to front. You are attempting to prove X and in doing so have found A, B and C which loosely corresponds with your conclusion. As for Edinburgh and Aberdeen, I am not saying that there is a prestige difference; I am simply saying your points do not prove that there isn't.
Talking about eliteness, which was your specific rebuttal: Edinburgh has a 57% offer rate, 503 average UCAS points. Aberdeen has a 95% offer rate, 458 average UCAS points.
Average earnings by uni show Edinburgh grads earn quite a bit more. I would use subject-specific, which are nearly identical, but the samples are small and generally unreliable. To be clear, I am not saying this will affect OP's future career; they should study where they will be happy and enjoy the time. Indeed, OP's future career will not be determined exclusively by their uni. But it is quite wrong to suggest that Edinburgh is essentially the same as Aberdeen because of cluster analysis and because you studied at RG and non-RG.