I believe the traditional small empire culture strat is a bit outdated. Main reason it's been considered the best for so long is that nobody really put serious effort into finding something better. @Anysense just did and showed sushi is a very serious contender on marathon. I think even when going for non-sushi culture a larger empire will be able to produce better results than small empires at least on epic and marathon. Quick speed it would be harder to find something much more efficient than the old strats.