B-pair is half a pawn better than B+N or N+N, so 6.5. I don't see how you would get B=N=3.5; that would make B+N+N=10.5, far stronger than Q (which was set 9 by definition), while in practice they offer equal chances. Archbishop=8.25 on this scale, as I already mentioned (Q - 0.75 Pawn).
The Kaufman scale uses Q=9.5, but it also has B=N=3.25, and B+B=7. Archbishop would be 8.75 then.
B-pair is half a pawn better than B+N or N+N, so 6.5. I don't see how you would get B=N=3.5; that would make B+N+N=10.5, far stronger than Q (which was set 9 by definition), while in practice they offer equal chances. Archbishop=8.25 on this scale, as I already mentioned (Q - 0.75 Pawn).
The Kaufman scale uses Q=9.5, but it also has B=N=3.25, and B+B=7. Archbishop would be 8.75 then.