Complex sentence: The mosaics found in Santa Maria Maggiore are combinations of different styles of mosaic art during the time, according to art scholar Cormack: the range of artistic expertise and the actual complexities of production can hardly be reduced to a mentality of copying.
Split into simpler sentences: The mosaics found in Santa Maria Maggiore are combinations of different styles of mosaic art during the time. As one scholar puts it the range of artistic expertise and the actual complexities of production can hardly be reduced to a mentality of copying.