Risto:
Great question. It was a problem of space in the book and what would be most helpful to most people. In my experience, most mountain runners and ski mountaineers don’t do ANY strength training. To suggest max strength training to people with minimal strength training background would, I thought be risky and irresponsible. So we focused on very basic exercises and Muscular Endurance.; Including a real strength training block can be useful for many mountain athletes. But a weak athlete will see good strength gains from doing an ME block even without a max strength block preceding it. If you choose to add this I recommend focusing on single-leg exercises like the Bulgarian Split Squat and Box Step Up rather than traditional lifts like deadlifts and squats.
I hope this helps,
Scott