I disagree with the suggestion about Adamant>Jolly on Excadrill because the simple fact is that, with the current trend of sand being fucking everywhere, it is important to outpace opposing adamant Excadrill and to tie with opposing jolly variants in the sand to minimise the team of your sand team rather ironically losing to variants of itself consistently when it is as insanely common as it is. In addition, with SD easily being the best variant and given that if it's not sweeping it is most likely RKing anyway, the added power isn't a complete necessity to the point where it requires that you run a positive nature to not be completely underwhelming.