As an example of the first, I now know that the Principality of Drachenpost has special troops known as “greatswordsmen”; foot soldiers who fight with two-handed swords. That’s a detail I might not have come up with if I was thinking purely in terms of role-playing.
And as an example of the second, when needing to bump up the point value of the starter army for the Barony of Rittergeist, I was able to incorporate the Knights of the Golden Heron, which I had worked up for the role-playing game, as a special force of Superior Drilled knights. It’s a little thing, but really adds character and color to otherwise-drab army lists, as well as giving some inspiration for painting the figures when the time comes.
I can see this working in all sorts of ways, with some of the ideas I’ve got floating around in my noggin. More to come.