Why not? The more extravagant looking Vikings you would leave out of course. Indeed the Strelets Anglo Saxons are too well armoured and some of the Vikings make better "rank and file" Anglo Saxon fyrd men.
The shield fort as in the Anglo Saxon - scildburh would not necessarily present a wall but were an organised body. It depended on the battle,terrain, location of the enemy and so on. The thegn (nobleman) was central to this together with the levy or muster known as the fyrd. In the 11th century the Danish influence was strong and so the differences between Anglo-Saxon and Viking appearances were narrowed. A lot depends on the period and the type of battle you choose. A fyrd defending a byrh in the 9/10th cent would probably be close to their settlement whereas the Vikings would be raiders. The Anglo Saxons would seek to have a numerical superiority and were lightly armoured and the Vikings would be better armoured and armed. The Osprey Warrior series 5. Anglo Saxon Thegn and 3. Viking Hersir are worth getting.