Here's my guess for "RV775" (= cherry picked RV770).
10 SIMDs
900 ALUs
40 TMUs

Yep.
90 ALUs per SIMD.
Cause that's what I see when I look at the die of RV770. There's nomore than 10 SIMDs but each of the ten SIMDs has infact 9, and not 8 clusters. No redundant TMU exists on RV770.