Since you asked, here is my personal opinion about fighting knives. Some will disagree; feel free to dismiss some or all of the thoughts below. I am peaceful man and a healer, so this is all purely hypothetic and or for the good folks in the US armed forces or law enforcement.
1. penetration, penetration, penetration…
I have sewn miles of knife wounds and operated on many more, and I can assure you that slash wounds are fairly ineffective, they are rarely fatal or fight stoppers. A fighting knife should be long and designed for stabbing and penetration rather than slashing or chopping. Ash style knives that are relatively short and fat are wonderful work/survival knives but poor fighters in my opinion; things like dssf are better. The longer the better.
2. speed kills…
Weight is the enemy of speed and speed wins knife fights, jet dogfights and fencing matches. A pure fighting knife, as opposed to an all purpose “survial” knife should be FAST and only thick/heavy enough to barely avoid breaking or bending excessively. A moab would not be my first choice here.
3. Good guard and sticky handle
Since a stabbing motion is what is effective, you want a knife that you can stab full force into hard material with WET hands and not run your palm and fingers forward onto the blade; the team geminis have the best fighting guard. Also, the handle material should be as sticky and graspable as possible; the worst thing you can do is lose your grip on the knife. I think the Res C handles are actually superior for a fighting knife.
4. Balance on the index finger (behind the choil)…
This is related to the speed issue on #2 but, a fighting knife should be fast and maneuverable. A knife with the balance on the index finger is neutrally balanced and will be the most maneuverable by definition. Many Busse aficionados love chopping (including me). Good choppers have a lot of forward weight like an axe, this forward weight is designed to MAINTAIN momentum in the direction of the swing and drive the blade into the wood. Maintaining forward momentum is however, by definition, the exact opposite of maneuverability (the ability to rapidly change direction) and maneuverability is what you want in a fight. Good choppers are poor fighters.
5. Unless you are going to try to penetrate body armor, the blade shapes with a large forward cutting edge like a sar, basic or mistress will cause more deep damage than something like a force one where the last inch at the tip creates a very small wound channel.
6. Knuckles and double edges are a bonus.
Lots of my personal BS here; sorry for the length. To be more direct. the Taliwacker, team Gemini, DSSF are good choices in that size bracket. The Sarge 7 has a great blade profile, but the handle in not the best for a fighter IMO. The Basic 10, thought a bit longer than you want, would be close to perfect if it was not relatively forward weighted. Also, I think the versatility of the knuckles should not be underestimated; I have not handled an Argonne Assault yet, and it is longer than you want, but it looks like an excellent fighter.