@Azel So from what I've gathered regarding Mass Combat homebrew:
DP should just write about tactical-scale encounters, if he wants to give an example of a conflict's general level of stakes, with a given set of sheets for singular troops. These would be largely fluff, with sheets created largely at request from him by players (or himself).
At this scale, we should already be on 4X rules, with regular D&D rules tacked on for "legendary hero" activities, when that level of abstraction is a detriment to narrative intent rather than an aide toward simplifying matters.
If you intended upon writing rules to resolve conflicts between armies of thousands, we should resolve to use those determinations when observing military activities play out 'on screen'.
@TalonofAnathrax mentioned earlier that whenever it comes time to roll out big changes, people mention "but I
like X about Y! We should keep Y because of X, but we can also do Z at the same time."
That feels relevant.
The two don't end up playing well together, because one person has one purpose and reason behind doing the first thing, and the person who is designing the new thing does not care at all for the first thing to begin with.
I feel like there should be some interplay between D&D mechanics and strategic scale mass combat, as at times it might not be practical to have no rules for tactical scale fights. But thinking about it, it just feels sort of all or nothing. If we're on screen when a
tactical-scale mass combat breaks out, we can kill an arbitrary number of standard units with relative impunity, even amongst armies with tons of special modifiers, immunities and bigger statistics as compared to human ones.
So the end result is it comes down to a knife fight between two roughly equivalent groups of hero units, with armies largely acting like set pieces and defeating the purpose of worrying about tactical-scale groups of combatants.