[militarist]

I remember, that it was supposed to be N but now - E. I keep it in mind.
The reason why I think Centaurs should be E based rather then N is that it will be just more logical and intuitively clean. Also steppe-based centaurs are not less logical then wood centaurs. I'm sure histiry knows both versions.

And then it's logical tie them to plain terrain switching them with B2s and B2N2s.

Nothing else, really. If not to count that E is in general more useful then N for non-communion use (E2 summon earch power->E3-> skelespam with some reinvig for example or anything else..E3 is much better then N2).