Saga Allied Warbands?

I've been pondering how to go about representing allied contingents in Saga, in other words, mixed forces from two or more factions. The reason for this is that I'd like to field an allied Danish contingent in my Cornish warband, as this is historically valid for the early to mid ninth century. In 838AD the West Welsh joined forces with the Danes who had been raiding up and down the coast, to combine their strength against a mutual enemy, the West Saxons under King Ecgbert..

The first idea I had was to add a couple of units of hearthguard or one of warriors to the Cornish army, then just use the equivalent slots on the Welsh battle board to handle both the Welsh and the Danes. This would be the easiest option and would let me keep the numbers down, incorporating the Vikings into the Cornish army as a couple of points in a six point standard sized force. This would mean, however, that the Viking attributes wouldn't be represented, which seemed a bit of a shame.

I think a better approach would be to use two battle boards instead of just the one, with four points worth of Danes and four points worth of Welsh, under a unified Cornish warlord's command. This would be an easy way to keep the best of both worlds without having to do too many units or paint too many figures, especially if the Danes were entirely hirdmen, rather warriors or levy. This might limit their battle board options but it would be easily manageable and a little less flimsy.

There are rules for eight point a side battles in the Saga main rulebook as well, which gives the whole thing a sprinkle of legitimacy. I quite like the idea of fielding a composite eight unit allied warband, as it would really look impressive and should be interesting to play with, combining the Welsh skirmish and missile characteristics with the melee abilities of the Vikings. I think it would look good too. It's the Welsh / Cornish first though before I get carried away.