in this case the blue arena has fallen below it's dynamic threshold. This will reduce the total cap in orange, hence you seeing 40 + over the limit, It most likely just occurred when you logged in, until more players get back into blue, orange will stay at 200 until more people get online.
You just have to adapt to the caps they were put in for good reason and the dynamic setup is the best solution in having TWO main arenas.
Personally I think they should have stuck to their guns and had early, mid and late war rides in their respective arenas without any caps.