2017 was an unusually strong year. Its hard to judge who of Gilbert, Greg and Sagan was the strongest, but I still stick with Greg there despite of Gilbert having the most spectacular performance. So Sagan is probably 3rd there despite being strong and probably over the whole cobbled season the best he had been - but how much did he win? Nothing really. Like this year where he have been much worse for some reason - Bora can't be too pleased with his classics performances so far, they have been disappointing, especially result-wise. This year i think all 3 of them are worse, especially Sagan, but the level is much more equal in general. There are no superman/supermen.
It honestly wouldn't surprise me if tried to experiment with some fancy stuff again due to the WCRR. Not too bright, but it doesn't really surprise me with Sagan.