Other way around, it’s a pseudonym created to work on the project, IIRC Lina got involved early-mid 2022 while Hector Martin started the project in late 2020 / early 2021.
They "just joined the project" and reverse engineered and developed the kernel drivers from relatively little prior work, in just a few months.
From afar they also seem to have a pretty ebullient and infectious personality and to stream a lot (we're talking 10h streams every few days: https://www.youtube.com/@AsahiLina/streams) which is impressive work and dedication.
What do you mean by "so much clout"..? She's one of the people who decided to work on the Asahi Linux project, and she's writing and streaming about the work she's doing and participating in mailing lists and IRC communities. Is that an unexpected amount of "clout"?