PE.
Do you know what method Kodak used when IIRC they put the words "Worlds Sharpest" on the new version TMY2 of the 400 ISO TMY film?

Crawley's method, Amateur Photographer 10 May 2008 confirmed that TMY2 gave a higher amplitude at both high and low frequencies, agreeing with this although as you indicate other factors are involved (probably outside the scope of this discussion but interesting to know what Kodak did.)

He noted other 400 ISO films have different advantages.