Unfortunately, wrong. Sharia is what your imam declares it to be, just as for a Jew Halacha is what your rabbi declares it to be, or for a Roman Catholic the Pope, speaking ex cathedra, declares dogma . You decide the extent to which you accept that. There are literalist imams and literalist ribs (the Lubavichter rebbe and the Satmar rebbe, may they rest in peace, come to mind.) While it does appear to be true that extreme literalists imams have gathered a following than have extreme literalist rabbis, that is a question of degree, not of fundamental difference. Islam and Judaism have divided themselves into several groups, Shiite and Sunni for example, based on the teachings of respected imams for Islam. Ultra-orthodox Jews, modern orthodox Jews (Mr. and Mrs. Kushner) Conservative, Reform and Reconstructionist Jews.
While Islam incorporates many extremes, so do Judaism and Christianity; in most cases followers reinterpret Scripture to make adherence to those extremes unnecessary.