We're playing a campaign set on shores of the Baltic, so I've just thrown together a folk art inspired pattern to use as a symbol for my Grail playing friend whose warband comes from rural parts of Poland
Nothing amazing, but I'm hardly a graphic designer, so I'm still kinda glad how it turned out

We also have a Heretic Naval Raiding Party, a Papal State Intervention Force, a Tatar inspired Iron Sultanate warband, a Pride dedicated Court Warband and a Trench Pilgrim band from destroyed Gotland (in our story the current conflict started when a bunch of Heretic submarines managed to sneak to Gotland, completely sack and slaughter the island and open a minor hellgate there). Sadly nobody is playing Prussians, even though they would be very fitting.

We've played 8 battles in total so far. We all have very little to zero wargaming experience and it's the first campaign for all of us, but having lots of fun so far.