I have the impression that in case .315 has max output, .215 has low output power (sometimes) .315 has low output, .215 has high output power (sometimes) but that both .215 and .315 can be very strong.

For example, 315 was relative weak (FM) for a while, and at that time .215 was very load with CW.

Object C is now best fit here.

Henk, PA3GUO