I can't fully agree. Uematsu is better at creating memorable melodies than Hamauzu. Also Hamauzu likes to stay in familiar territory with his specific sound, while Uematsu is more willing to add variety to an OST.
I mean, I don't disagree. Uematsu is a more gifted melody writer, no doubt. He has a distinctive style, yet can really think outside of the box sometimes. He's like the ABBA of video game composers.
Hamauzu is more in tune with the "craft", but has a limited range like you said. But he has great
taste (aesthetics are often overlooked when comparing raw ability/technique) -- adrenaline-pumping, pulsating rhythms on top of otherwordly chord progressions and virtuosic solos.
What I've noticed over the years is, the older I get, the more pleasing to the ear I find the Hamauzu sound compared to Uematsu (whom I still love). In summary, I'd say Uematsu is melody first, whereas Hamauzu is harmony first in how they construct their pieces.