We do practice erroneous air data indications.
The solution is to manage the triangle of Pitch / Power / Airspeed. Power can be obtained by charts in the QRH. Or you can just set it somewhere in the middle.
But I have found, the best solution to unreliable indications is to use the flight path vector. Just put it on the horizon, set a normal power setting and you're golden. When it is time for the approach just put it 3 degrees below the horizon. No idea why this isn't taught.