In France, I saw guns with a long tang trigger guard, AND an extension on the top that ran until just behind the comb. I think the name translated to "squirrel tail" extension, but, it was one of those things that made my eyes glaze over, and start thinking about getting another beer.
I would guess a long tang, properly fitted, adds rigidity to the wrist. It for sure adds a place to put some more good engraving, and an initial shield, surrounded by platinum wire.
Hey, great blog, by the way.
Best,
Ted