I was working on my Chainmail Arena idea over the summer, but then it stalled out. I was making troop type cards, and it was fairly tedious. Now I have realized my mistake. I was making individual cards for each individual troop. But since I'm no longer planning to use the man-to-man combat tables, I can make cards for groups of troops. I can then give them a bit of flavor (Cimmerian skirmishers, Orcish Brute Squad, Dwarves of the Crystal Caverns, etc.) and have a set number of 'figures' for each one that will determine the cost and combat power of each type. I may have posted about this idea already, it's been on my mind for a while, but even after coming to the realization, I never got back to work on the project.
Also, following some of the ideas people have put out for using Chainmail combat in OD&D, I'll be giving stats for all fantastic troop types so there's a chance that troopers can hurt and kill them. It makes sense to me that a big mass of archers or pikemen or whatever should be able to eventually take down giants, rocs, and dragons (assuming the latter two come to ground in the case of pikemen).
Even though the troop types will be in groups, I plan to just use one token/icon for the unit. Realistically, I'll only be playing this online (except maybe some play tests with the boys) so no need to clutter up the map with dozens of figures. Yes, I realize in the actual rules 1 figure represents 20 men. I'm just saying that for a force of hundreds, 1 figure is still enough for this game. That 1 figure will just take more hits and suffer reductions in combat value for those hits before it's eliminated.
I'm also tempted to try and meld Chainmail/Dungeon! board game style combat into the new revision of my house rules for D&D, but that's probably too much of a switch for my players.