It's not just about power. There's a tone you get from a larger string section, for example, that you cannot replicate simply by amplifying a single violin. You also cannot entirely replicate it by using some kind of digital enhancement system. It's not the first time Mackintosh has done this. In the Miss Saigon revival, which (in the UK) cut the orchestra down to 16, the difference from the original was noticeable, and it was *not* an improvement.