What I'm saying is that it might be the case that "capability c" (somehow measures as a positive scalar) of your fused sensor system is not the sum c = c_1 + ... + c_n of the capabilties of each sensor c_i, but more like c = (c_1^p + ... + c_n^p)^(1/p) where p is a large power. The case p = 1 is where every sensor contributes to the whole system with perfect efficiency. The case p = infinity, i.e. c = max (c_1, ..., c_n) is where really only the best sensor does all the work and the weaker sensors can not add anything useful. The case of p > 1 somewhat large represents that all sensors contribute but the real heavy work is being done by the best sensor and other sensors only have significant impact if they have roughly equal capability. So I believe that the team at Tesla has the intuition that p is too big for radar to be worth it.
