Well, that is, of course correct (that te wine should star). I did a test with Château Raymond-Lafon, the neighbour to Château Yquem mainly to test the desserts, but one course in the test was a sous vided salmon (not smoked) with green pea puree, that worked really well, the sweetness of the wine was balanced by the saltiness of the fish together with the sweetness of the fish. I have had sweet white wines together with seafood before and it is truly a great combo. I have also tried it at two different Michelin stared restaurants.