I went back to the BixBench benchmark which they mentioned. I couldn't find official results for Anthropic models, but I found a project taking Opus 4.6 from 65.3% to 92.0% (which would be above GPT-Rosalind) with nearly 200 carefully crafted skills [1]. There also appears to be competitive competitor models with scores on par with this tuned GPT.

[1] https://github.com/jaechang-hits/SciAgent-Skills