Aerobic workouts vs training hikes

This is more me thinking out loud, but if someone could let me know if I’m on the right track in terms of thinking/strategy, I’d appreciate it.

Based on my Aerobic Threshold Test, I have some work to do in terms of ADS. The top of my zone 2 is 120 and based on a recent hike I went on, anything vertical quickly pushes my HR up above that, even at a very slow pace.

I am training using the 16 week Mountaineering plan with my big climb just 17 weeks away. Traditionally, I would tackle the season by working my way up to it via higher and longer trails and heavier packs. But given my goal is not just get through my climb but to thrive, I realize that this isn’t the best way.

Based on the plan, I should replace my training hikes with elevated treadmill time. Hikes I do go on, I should target flatter, shorter, and unweighted until my zone 2 HR can handle bigger challenges. The hard part to wrap my head around: The 2 hour elevated treadmill at HR 2 will do more for me in the long run than the 4 hour 3k feet hike.

Do I have this right?