In my fairly realistic fantasy campaign, I've run into two issues. I've got a few thoughts on how to solve them, but I figured I'd share what I've come up with so far. See if this sounds right to you, and let me know if you have other ways of addressing these issues(other than hand-waving, of course).
Big Fights:
I'm using Mass Combat, but I find that I'm a little worried about making templates for NPCs in GURPS-scale that relate well to their Mass Combat stats. For instance, I might make a unit of fearsome mercenaries that operate as elite, well-armed foes in Mass Combat, but if their GURPS stats don't stack up well, they might be pushovers in personal combat.
I understand that unit cohesion and discipline are principal in making them fierce combatants in Mass Combat, but if tough foes in Mass Combat turn out to be reliably easy to kill in personal combat, my players will doubtless seek small battles for mechanical reasons rather than role-playing reasons. No amount of explaining 'oh, well, their teamwork is better when fighting in large battles' will make that acceptable to my way of thinking.
My thought for this is similar to hari's suggested skill values
here. I might state something along the lines that a given Mass Combat TS(the most important stat for me to translate properly), average troops will have an offensive skill, a defensive skill, and a soldiering skill at an average of 10-11, and scale the others from there. However, ST, HP, and DR seem like they'd be big factors in the setting, too, so I'd like to incorporate them into the guideline.
And the second issue...
Long Fights: This is a similar issue, but unrelated to Mass Combat per se. Say you have major NPCs or the PCs themselves fighting an absurdly long, sustained combat--the sort that would be stretched out over as much as an hour--but it wouldn't involve enough combatants to merit bringing Mass Combat into play. For instance, I'm imagining something where less than five skilled warriors stand on the far side of a narrow bridge and see how long they can hold off a horde of unskilled fighters. If played on a one-second time-scale, this would be a tedious fight rather than an exciting one, since it could last hundreds (or thousands!) of turns.
I could use Martial Arts' tournament detailed method to resolve this, but I think that will still be too tedious, and the quick method would be too cruel to use on PCs with any regularity, since a single botch could easily kill them without narrative lead-in or dramatic build-up.
For resolving long, small-scale fights with fewer dice rolls, I think a turn scale of 1 minute sounds good. I imagine that most of the same maneuevers normally available to players would be viable, but would indicate their strategy over an entire minute instead. All attack rolls would be at +1, and all defenses at -1, to illustrate the fact that overtime the odds creep into the favor of offense.
For damage, I'm a little at my wit's end on how to resolve this to my satisfaction. Again, I want this long fight format to relate well to second-by-second combat. Perhaps use the attack's margin of success, similar to the RoF procedure, where each point of success (relative to the dodge roll) is an additional hit, with each hit causing the usual amount of damage?
So, anyways, thoughts and comments would be appreciated. Let me know if you foresee any problems with my potential solutions, or a more elegant way of getting around the issues at hand.