Guys, you are misunderstanding the whole situation.
The topic of this thread is the Impossible combination of Abilities/moves, not the comparison with Smogon tier list. The topic of this thread is not about Pokemon that have been put in UBER tier in Gen 7, but the combination of moves and abilities that cannot be obtainable in the Pokemon games normally.
I will make you an Example:
In generation one THERE WERE NO ABILITIES.
Machamp could learn the move Fissure in Generation 1, cause Fissure was a TM back in the days.
Fissure TM has been removed in the next generations.
With the PokeBank and Pokemon Red/blue/Yellow in virtual console on Nintendo 3DS, a Machamp from Pokemon Red/blue/Yellow can be transfered to the new games, but it will hold only his Hidden ability(it's a rule of these transfers).
Now, in Gen7 Pokemon Games we can have a Machamp with fissure, but the only ability available for that Machamp is Steadfast.
So, it's IMPOSSIBLE to find a Machamp No Guard + Fissure.
Extend this thing to all pokemons that have the same problem and u get the topic of this thread.
This is not to discuss tier lists, but to discuss about impossible combinations. Spend more than 2 minutes to read please.