Lyadov was actually very gifted but notorious for lazyness. In fact, he was Diaghilev's pick for The Firebird, but the entrepreneur got tired of waiting through so many postponements and then somebody mentioned the Fireworks to him (bless his soul).
Mike: Same recognizable commercial style is one thing, same music exactly is another. Yes, I credit Elfman for the entire jingly-tingly-percussion/celeste for the main themes/impish rhythms school of soundtracks.
Bill: I happily purchased a heavily discounted EMI 'Complete Vaughn-Williams symphomies' about 15 years ago, and enjoy them on the odd occasion. Great composer, although I think his influence on soundtracks outside of the UK is based on influences he adopted during his European sojourn. I would pick Walton as wielding a bigger international influence in soundtracks respect, although I don't pretend to be an expert in this regard. As to VW, have a listen to a beautiful but less known work - Flos Campi, curiously written for solo viola, choir and orchestra. The second movement of his piano concerto is also a favourite haunt of mine.
I also believe that we lean a little too much on John Williams for his (admittedly true) influences. He is his own composer - except where Spielberg was too fond of the temp tracks - one of the few directors who know music (Holst's ghost is prevalent for this reason), but his natural pulses and rhythms are better than Holst's as well as the obvious American influences (Copland, Bernstein, etc.). I find that he imitates Mahler a lot more often than Rachmaninov (at least from the mid-'70s onwards), as Williams and the Russian are vastly different people. One is full of positivity, the other clangs death knells with every work; one is a supreme melodist, the other composed the main theme to Schindler's List... Like day and night in fact.