Vanessa Helder may be a little too far outside the purview of the 'NW Modernism' exhibit, and I think there actually is a Helmi or two, but you're absolutely right - women artists strangely neglected, and many other worthies underrepresented. Your basic assessment is correct - a great show, but they should've called it 'Tobey & Graves and a Few of their Pals', rather than claiming to present a comprehensive overview.
As for Leo Kenney, his work is so mind-zappingly great, I can't bring myself to complain about SAM's bias toward him. Thanks for good article.

What's super weird about the way the Asian influences are presented in the SAM exhibit is that it completely ignores the influences of Horiuchi and Tsutakawa on Tobey, Callahan and others. Horiuchi was the one who originally introduced Tobey and the others of the 'big four' to Sumi painting, which prompted a massive production of art from Tobey, and many pieces from the others as well. To relegate them to this secondary status within this art movement does the artists an injustice, and in a way changes the history. There's an exhibition of NW Art going on at the Art REsource near Pioneer Square, and while it is smaller, it is much more comprehensive and equally representative, and has a better selection of medium than the SAM exhibit.