You're using the term LSM incorrectly. LSM is a form of QPSK modulation developed by Motorola; it is not the term used for describing simulcast distortion or multi-path.
Scanners are not "susceptible to LSM", they are susceptible to simulcast distortion or multi-path from LSM, or H-DQPSK, or other QPSK types of modulation.
That is like saying people don't die from being shot, they die from the hole...or that people don't die from falling, they die from impact.
Paul