The interesting thing is that Vikings and Greeks had similar formation fight , but Greeks had a better discipline , training , organization and numbers, while Eventually what favored most the vikings was a more modern technological level of the weaponry.
I'm not sure I'd agree with the discipline and training. Except for the Spartans, they were probably very comparable. As in, basic weapon skills and how to stay in formation, and a knowledge that staying in formation was fundamental, maybe not much more than that for the average man in line. We do know that the Greeks organized themselves into files and units which could very efficiently be deployed into line, but I don't know if anything similar is known for the Viking era. Of course, if a mob in column is just pouring into a mob in line, with the generally accepted standard of "better guys in front", that can be pretty quick and efficient, too! In my reenacting experience, it really doesn't take any prior training to line up behind the guy in front of you so that you can thrust your spear over his shoulder, so "files" naturally occur.
Both the Norse and the Classical Greeks raised their military with a system of obligations based on social status and wealth. The first hoplites were simply the upper classes, both because they had the money for armor and weapons, and because they wanted to stay that way--don't arm the poor if you want to stay rich. Eventually the poor were being enlisted and armed by wealthy men as supporters, either as skirmishers or as hoplites, and in some cities many poorer men signed up as rowers with the fleet. Cultures in the Viking era had regulations about who had military obligations, and what a man of any particular wealth level needed to have for equipment. So it was different but achieved a similar end, a core of armored elite backed by more lightly armored or unarmored commoners.
I suspect a Viking army would be very impressed with the amount of armor in a Greek phalanx! While the Greeks would be very impressed by long swords and those mucking great axes, though of course both sides would mainly fight with spears. You can do things with an aspis that you can't do with a Viking shield, and vice versa. All that long blond hair would be a real turn-on for the Greeks...
Once you get into the Hellenistic era, things change. I *really* don't think I'd want to be in a Viking force facing a Macedonian pike phalanx! Heck, NObody did. There'd also be supporting heavy and light infantry, archers, and lots of cavalry. Hellenistic armies were just BIG, overall, probably larger even on average than some of the great Viking forces that we know of. That went along with more training and discipline, more complex and organized logistics, etc. It was a real army, not just an ad hoc force or militia levy.
Now, I don't know any of the possible differences between Norse armies of different times and places. I don't even know how much of that might be known, beyond some low-level basics. Also not sure how much functional difference it might make, in that era, though obviously a force of professional housecarls is going to have some advantages over local fyrd!
There were developments in metallurgy and technology between the Greek era and the Vikings. But there were also massive changes in infrastructure and economics. How much that all made one culture better on the battlefield than the other is much harder to say! In the end, I'd lean towards metallurgy as one of the less important changes. Infrastructure and production is a much bigger factor, because it affects how many men you can arm and armor. Of course, that goes hand-in-hand with social changes, as well.
Too many variables!
Matthew
