Ground perfectly embodies the proverb "The more things change, the more they stay the same." Just looking at select stats between MPL and MWP reveals some uncanny similarities:
- Excadrill (aka sand) usage: 60% in MWP, 58.82% in MPL
- Excadrill (aka sand) win rate: 41.67% in MWP, 40% in MPL
Seeing how similar those numbers are, one might assume that the teams are virtually unchanged from MPL. Yet it is remarkable just how quickly everybody rejected the MPL sand team and decided on the same replacement.
Taking a step back for a moment, it is worth noting that Ground can in some sense be considered two different types. There are sand teams, which are highly offensive and typically take the structure

[Flex]. Then there are teams which were formerly described as "sandless" but now might be better described as "bulky Ground" teams which have more flexible team structures but typically include Gliscor and potentially Ting-Lu, Iron Treads, and so forth.
With regard to Sand teams, in MPL the near-universal choice in the flex slot was Garchomp. In MWP, out of the 12 times Excadrill was used, Garchomp was only a teammate 4 times. Instead,
Great Tusk occupied that slot 7 times, usually as a Scarfer. Compared to Garchomp, which had various sets including Spike stack, setup sweeper with SD Scale Shot, and mixed attacker with Life Orb, Great Tusk offers speed control that doesn't require Sand to be set up first. It also aims to alleviate the challenging Dark matchup which Ground lost every time in MPL.
Unfortunately, these effectiveness of these changes is very much in question. The type's already low 35% win rate, upon inspection, is actually propped up by 3 instances of the mirror. Removing them yields a win rate of just 29% (4/14) - the lowest of any type that won at least one game. Moreover, Excadrill won 5 times, of which 3 of them were this very mirror matchup. Removing them yields a win rate of 29% (2/7), exactly the same as the type's win rate (this also means that teams without Excadrill have the same win rate). These results suggest that sand and bulky teams are both lackluster in the meta. This is surprising since the top three types by usage in this MWP were Dragon, Steel, and Water, the first two of which are generally considered very playable for Ground and the third is team-dependent. This hints at deeper issues about the type, how it is piloted, or when people decide to bring it at all.
For completeness, here are the only two non-mirror Sand wins:
Xiri vs Ringmaster Uta (Ground vs Steel, Week 1) - Steel was never able to stop Gravity
Xiri vs Fogbound Lake (Ground vs Water, Week 5) - Water lacking Oger-W has a lot of trouble against Ground.