Unaware Clef being worn down is this huge over exaggeration lol when 1. you need a good 2+ Spikes + Rock to wear it down effectively 2. has clerical support to top it off
http://replay.pokemonshowdown.com/smogtours-ou-83951
This was an Stour game yesterday between me and Hikari. What should be taken away from this is that Hikaris Unaware Clefable was able to support its team to the point where it necessitated a lot of offensive pressure to keep things under control, stopped my Slowbro from winning through Calm Mind (granted it was poisoned but the point still stands), was able to scout Heatrans set for an appropriate switch, and even make sure Manaphy could come in multiple times to punish slower builds. The unaware set is a staple on defensive builds for its ability to be one of the most anti-offensive counter measures in the game and being able to slow down the likes of Manaphy, Serperior, Garchomp, Weavile in one slot is kind of nuts when Unaware runs variants such as Wish / CM, Thunder Wave, and the classic set. Think S is a given.
Support doesn't have the prowess that CM or Unaware has. Nothing else needs to be said.
Scarf Latios is a very team specific asset one that is the result of threat control that is often times shaky, unreliable, and to some degree not even necessary. I can explain more but Scarf Latios is kind of a one hit wonder.
Hex Gar is again, too team specific. Although there's different variants you can utilize it only punishes super passive builds and normally needs Substitue to be successful or have any remote chance.
Um....Two attacks M-Gyarados should drop to A- lol but like if you're gonna drop that to A-, Scarf Latios is gonna be a B+ set. M-Gyarados wants 3 coverage moves and a secondary partner to break stall and bulky builds. Saying A- cause it's not really more effective than something like AV Azu.