Mass Combat,

A few years ago in the Tales of Durien,
The heroes were accompanying a contingent of the Lord’s men (1/2 a dozen mounted guardsmen) tracking down a bowahr raiding party (really big orc-likes), eventually finding them. What ensued was a poorly improvised “standard battle” involving the PCs and a few random rolls with descriptions to detail the guard’s battle.

A few weeks ago during the Tales of the Northern Ways,
The heroes led 50 armed soldiers from the city and 20 outcast barbarians against 100 lycanthropes of Malar. It was handled much the same way.

I’ve been creating/running a simulationist game & I’ve no satisfying (rules-wise) methodology for handling of massed combat.

I plan on getting more involved in mass warfare in my setting & was wondering if anyone had any suggestions on a system/systems that I could check out for inspiration.

If you're creating your own game and looking for some inspiration, you may want to post this in the First Thoughts forum.  That being said:

There are plenty of different mass combat systems out there for inspiration.  The War Machine rules in the D&D Companion Set was always useful for quick and dirty mass combat, and Ars Magica's Ordo Nobilis provides an extremely crunchy system based on number of "lance units."

On the other hand, I always found the first edition of Stormbringer's "mass combat" system to be elegant in its simplicity...the GM simply decided the outcome of any large scale battle, while the player's actions only affect what happens in their immediate surroundings.  You may win a battle or two, only to find you've lost the war, via GM fiat!

Well, do you want RPG elements to make a mass-combat system within your RPG or a wargaming system that will adapt to whatever elements you want to throw in?

For a miniatures wargaming system oriented towards fantasy (or historical) and towards customisation, have a look at ARES from Majestic Twelve Games: http://www.mj12games.com. It's good for around 20-30 a side and is an open order (ie no ranks or tight infantry formations) game. I have been interested by, but have never played, Battlegrounds: Fantasy Warfare which handles massed infantry formations by printing them out on paper, but I don't know how customisable it is.

If you want a grander, more strategic view of the battlefield, MJ12 has "For the Masses" which works on a hex-grid and therefore should work well with tokens if you want. I assume it is customisable, ie, you can make units to fight and act how you want them to. But again, this assumes you want to "wargame out" the conflicts (I know I would!). If you want to take a wargame-ish approach, check out the forums on MJ12games.com, where you may very well get some good advice from experienced number-crunchers.