Just took some time to look over the mass combat system. Wulf done good, as it's tied directly to CR/EL and the usual 1d20+X vs. DC Y system.
I would say it infinitely scales ... you can field several full armies easily as with mixed groups it pretty much boils down to "get your guys there" and "pit their EL vs. the other guy's EL". Very simple, but it makes alot of sense. How do you adjudicate fifteen flying pegusai and thirteen thri-kreen on the ground verses twenty-six Ogres? EL vs. EL throwdown.
It's nicely complicated with ground/battlefield types and conditions ... settled lands vs. entrenched areas, etc. You choose a secret strategic end and fight for it, which determines a few things about the combat at the end. You might be fighting through to break their lines of command while they're fighting to break the will of the settled peoples so they can no longer give succor to your own troops, etc.
I will say it starts to get hairy around "Magic". Magic breaks down into "well, seriously, how many people COULD he frag?" and the maximum number of affected targets then gives you a bonus on the ELvsEL throwdown. If the spells are coming from a limited resource (casters, mostly, but spell-like abilities and maybe lots of wands) then you reduce your own effective EL by using up magical resources. I have to look at it a while longer ... the simplicity is probably the best part with the magic system, but Grease is better than, say, a 9th level caster's Scorching Ray. I need to think on it as I'm trying to incorporate the BCCS magic system, which has a fully flexible area system. A 4th level caster could, say, toss down a 20' radius spell ... it's 20' ... but only does 1d4 nonlethal damage with a save for half. So then you get into determining what's an EFFECTIVE spell against what group, etc, but that's minor enough I'm not going to sweat it.
DRAGON CR: Yea, we realized that the CR on the dragon was "off" because WotC underscored dragons, which is why I wanted to see what the REAL CR of that thing was. Played intelligently, D&D dragons can seriously throw off an encounter if you don't know what the REAL CR is.
--fje