So I have tried various systems for mass combat over the years with D&D and most recently used the system from Strongholds and Followers which is innovative but we found it too slow and disjointed from the PCs actions. My PCs actually preferred to be directly in command of the units or fight on the field of battle. And the whole “My PC takes a turn, and then my unit” where the units are rolling a to-hit and damage as well, just bogged things down. I do have fond memories of AD&D Battlesystem but thats a miniature game which is too detailed for me. I ended up falling back on the all D&D Basic’s Warmachine from the Companion Boxed Set.
To help me manage my campaigns units I created a google sheet where you can punch in the numbers and get the Battle Rating. Not tested in anger yet, but will be shortly as my Oriental Adventure campaign becomes more political and militaristic. Shared here for both my PCs and anyone else that wants to use it. I will also be using the domain rules from the same book.
Banner Credit: Larry Elmore, “Companion Boxed Set”. TSR.