This is statistics.

At one point, I purposely researched this question — it turned out that the number of key objects (roads, external dwellings, Griffin Conservatories, hives) for red is roughly 50% greater than for blue. From other pairs, I looked at Castle-Barbarian, and there the difference fluctuated between 0 and 20% as more stats were gathered (if my memory serves me).

When I posted these calculations on the forum, I was told this was a well-known fact, something like "the terrain distribution is worse for blue than usual."

Why that is — no idea. I only looked at SM maps.

Maybe an experimental error :)