My view is that if you take someone with philosophical talents and interests (presumably inherited or caused by the environment in a hard-to-control manner) , you can make a better philosopher out of them by having them study more math and science than the typical education for a philosopher. But if you take someone with little philosophical talent and interest and do the same, they'll just become mathematicians and scientists.

I think this is probably similar to the views of SIAI people, and your quote doesn't contradict my understanding.

Unfortunately none of core singinst guys seem to have any interesting accomplishments in math or have actually studied that math in depth; it is a very insightful remark by Luke but it'd be great if they have applied it to themselves; otherwise it just looks like Dunning-Kruger effect. I don't see any reason to think that the elite math references are anything but lame signaling that is usually done by those whom don't know math enough to properly signal the knowledge (by actually doing something new in math). Sadly it works: if you use jargon and you say something like what Luke said, then some of the people whom can't independently evaluate your math skills, will assume it must be very high. Meanwhile I will assume it to be rather low because those with genuinely high skill will signal such skill in different way.