This is the same for a lot of openings, I play the Classical Sicilian, the critical variation that all the GMs play is the Richter-Rauzer, and I see that like 1 in 100 games.
The fact that a line is not critical doesn't mean you will be "punishing" it though. White can play a lot of ways against the Dutch and have a small plus. The flank openings tend to mean that White gets a free hand in the early going. It's not possible to map out all the stuff White might play.
Also a little confused about why you have books on the Classical AND Stonewall AND Leningrad Dutch.
I have bone to pick with the Dutch theory! Its consistently incomplete!
Every single book I bought ( 5 total ) focuses on the critical variation being the fianchetto. I'm currently at 2000 Blitz and rarely face it, like RARELY! So I'm stuck navigating, at what I can mostly call, bloody ''sample'' chapters that'll skim the theory. -oh yah, play this way and you'll get an advantage. OKAY! so its not critical. BUT HOW DO I PUNISH IT THEN ! WHY IS IT NOT CRITICAL !? And don't you go saying: Yah, obviously engine gives it a +0.5 edge over 0.3 edge.. LIKE DUUUH
So now I'm stuck to trial and error, which is fine, I did get to a respectable Elo by myself at the end of the day. Or choose a different opening......... F R U S T R A T E D ! ! !
I got
Mihail Marin : Leningrad dutch book 1 and 2
Killer Dutch by Simon Williams: Book & Chessable course
Stonewall Dutch by Nikola Sedlak
Starting out: Dutch defence by Neil McDonald