While who exactly owned the Sutton-Hoo helmet is conjecture, we certainly know it was a very expensive and kingly helmet. Now, I know not much variety is possible if you stick to the five (!) Saxon helmets we've found. And I've been able to identify only three of them in the whole Saxon army, but that's another matter alltogether. Almost the entirety of some of the Saxon units are wearing carbon-copies of the Sutton-Hoo Helmet. That seems unrealistic, considering it was found in a King or Nobleman's ship burial. It's not something everyone would have.
The other two helmets they used are accurate and what a normal Saxon would wear, namely the bowl helm Hengest (props on noble who actually historically existed in this game rather than Rome II's random people) wears and the Coppergate helmets many of the Saxons wear.
But yes, I'm curious, am I mistaken in thinking they're pretty rich if they are almost all wearing a Sutton-Hoo helmet?