This isn’t right.

Zesty Gourmand wasn’t in Season 8, but neither were the others, except Chancellor Neighsay. The OP is suggesting that this is a Mane 6 group of casual villains that have caused quite some disruption.
 
For more than a few reasons, Cozy Glow and Chancellor Neighsay should be replaced with Suri Polomare and Lightning Dust.
 
Besides, the other 5, or others mentioned on this list, didn’t nearly destroy magic in Equestria, doom the Mane 6 to Tartarus, and vie for title of Empress. The filly is more in the big league of villains.

Was Zesty Gourmand in season 8?

Did Zesty Gourmand really come back in season 8?

@Sixes&Sevens  
I like that, but I’d switch Zesty and Svengallop.
 
Zesty sucked all the joy out of all those restaurants by making them sell tasteless food and setting a bland and boring atmosphere while Svengallop was greedy and extorted anypony that wanted Coloratura to preform for them.

@Sixes&Sevens  
I expected such an idea in the sixth season, but it did not happen

@Sixes&Sevens  
How about being just plain cruel. It did say she’ll be taking over the school.

@LictorOmega  
I expected such an idea in the sixth season, but it did not happen

@genervt  
The most evil one, it’s always the most cute and adorable one.

I don’t get it

Just to add fuel to this fire:  
Neighsay is the anti-Twilight, a rules-obsessed scholar who is also a bigot  
Zesty is the anti-Rarity, a high-class trend-setter who ruthlessly crushes deviation  
Svengallop is the anti-Pinkie, in charge of big events but who crushes out the joy  
Gladmane is the anti-Applejack, using dishonest means to keep his business solvent  
Wind Rider is the anti-Dash, a famous egotistical racer who turned his back on what it means to be a Wonderbolt  
I suppose, therefore, that the remaining spot will be filled by an anti-Fluttershy, perhaps a pegasus who mistreats animals for their own gain.

I don’t see any true correlation between these characters aside serving the temporary antagonist for an episode.

Conspiracy Six