Cap 56 depending on the type of system in your aircraft I would carefully check the small print in the AFM as you may not be allowed to approach and land at an airport with cat II weather after the loss of system A. The certification rules may require that both channels of your system to be working for a coupled descent below Cat 1 minima.
Why should you expect a manual landing in Cat 2 to be as demanding, or more so, than a normal approach and landing. The assumptions in aircraft and operational certification are that any licensed crew will be sufficiently will trained, nor require exceptional skill, etc, to land an aircraft within the limits laid down.