Apologies if this has been dealt with before, but any suggestions for Scots Irish proxies? Thinking 5th Cent AD period.

When I did the Saga in 6mm project (arguably later than your timescales) I used a lot of different codes to make the 12 basic factions we used.  Perhaps not spot on but starting here could give you some ideas. Here a link to part 2 that discusses the Scottish and Irish factions.  https://rollaone.com/2016/05/18/saga-in-6mm-part-2/

Good Luck!

Thanks. Might be the way to go. I'll look at those ideas.

I ended up with a bunch of Moorish infantry from a halted project that I am trying to work into my current 6mm Vikings build. I was considering using them as Welsh or Irish light troops. Not a perfect match but a clever paint job should pull them in.

Now if I can only figure out how to work some Hittite spearmen into the Dark Ages theme.