[RobT]

Jim McDougall,
Your point about weapons being worn as status and fashion can’t be overemphasized. For anyone of the culture, the sumptuousness of man’s sidearm allowed the viewer to get a good idea of the wearer’s wealth and power. This display could actually act as a deterrent to physical conflict as, no matter how justified, an attack on a rich individual by a less affluent person put not only the assailant at grave risk of retaliation by all the forces that wealth can summon but also placed the attacker’s family in danger of the same.
An example of this status/authority is a koummya in my collection with a chapeau de gendarme pommel. The blade is noticeably larger than average and the sheath is a good bit larger than average but the pommel measures 8” (20.32cm) across and is about 5” (12.7cm) high. Even though the blade is a very good one, I can’t imagine effectively using a dagger with a pommel the size of a luncheon plate. The only thing I can think of is this ensemble was designed and worn as a very visible symbol of authority.

Changdao,
I won’t address the use or utility of the sword size flyssa other than to point out that the base of the blade extends far below the hilt and that would be enough to stop the user’s hand from traveling up the blade on the thrust. This feature on the dagger size flyssa makes them well suited for thrusting. Any mechanism that prevents the hand from going up the blade will do. It doesn’t have to be a guard. For example, the hilt ring that is designed to fit between the middle and ring fingers on a khukri will work.
I have read that the reason the khyber knife is called a knife was because it was used to stab overhand with a pugio grip (aka ice pick grip or reverse grip). I have also seen a period drawing showing an Afghan fighter holding a khyber knife in this manner while attacking a British trooper. In any event, the khyber knife with its sharp, quick tip is ideally designed for thrusting and stabbing. Not only does the heel of blade extend far below the hilt, the heel is slightly concave thus making it impossible for the user’s hand to slide up the blade on the thrust. In addition to this, the hilt ferrule has an extension that runs down the heel of the blade and forms a cushion for the hand. Whatever British reports you have read notwithstanding, I find it impossible to believe a knife so carefully designed for thrusting and stabbing wasn’t used that way at least some of the time.

Sincerely,
RobT