You missed my point and you're putting words in my mouth, Preston.

I'm not saying that they cannot perform on the battlefield. I'm saying if you want to compare two units you need to compare them to each other. There has to be a correlation between the two.

Comparing on the battlefield is still a valid testin itself, in which you can see how effective they are as support for their army. BUT, you're not comparing the two units in question to each other, because there are so many other units with varying stats on the battlefield at the same time that can affect the outcome of any encounter differently.
In other words, you'd have to compare all the stats and performance of all the other units in the battle and how they affected the battle in order to determine how effective the spartans and sacred band are in comparison.
That's too much to test. Too many variables that can change too easily.
I'll stop discussing this now as no one seems to get what I'm saying...
Carrying on talking about barbs and sels.

Preston, I use 13,500 denarii btw.