My *sense*(as a keen amateur writing here mostly to challenge my knowledge) is that it depends on how long of a macro cycle and mesocyle you have planned for capacity (base) plus utilization (intensity/specificity), and what strengths/weaknesses you are coming in with, what goals you have, and what terrain/gym options and preferences you have. I think that with lots of time, having a big MaxS gym focused block in the base may be just fine/good (I did that this yr), but I also see advice/plans (e.g. big vert) to layer in MaxS specific workouts (hill sprints) with ME (gym) early in base with options for both specific (hill sprints) and gym focused….
For example, this yr after my ~8 week transition where I did lots of gym General Strength progression I went into an 8 week gym based MaxS block because I felt like exploring that more, and it works well with my seasonal weather issues. I am now switching to another base block with 1x gym ME and 1x hill bounding MaxS per week, then will be shifting after that to an intensity block with gym ME plus specific ME mix. My goals are different (ski mountaineering and mountain running) so upper body focus is different. I’m going to guess that the more expert advice might say: if you have time, do 2x gym MaxS lower and upper mix (as per TFTNA MaxS recommendations), then part way through winter shift into more specific MaxS and ME mix….????