A quick Google showed not a lot for the Franks, so I decided to use a bit of artistic licence. The Commander is St Guntram or 'War Raven' so I found some suitable Raven iconography (there are loads around for Vikings, but I wanted something different), Mummolus, his favourite general got some early version of the Burgundian ragged cross, Childebert II the bees that were later appropriated by Napoleon, and Chilperic, being a loyal Gallo-Roman of Provencal, got a pretty standard 'Byzantine' style Labarum.
They were all drawn onto standard paper freehand in pencil, and then painted carefully by hand.
|Guntram's War Raven banner
|Chilperic's 'Late Roman' Labarum
|All of them together
Overall, while I took a quick and dirty painting method for these guys, I am pretty happy with the overall result.