>other pony defeat earth ponies
All residents of Equestria are clearly insane. TLDR [s]They all win, depending on circumstances.[/s]
Unihorns have violent lasor blasts with magic spewing everywhere. On the other hand they have lasers, and time travel, and teleportation, and weird spells that just work.
Pegisussikussus are wingy, and while they do weather stuff growing things is not a forte. Raiders, pirates, and vagabonds, maybe a military but at the current tech level the playing field is more equal. They loose the flight advantage. I mean weather power is destructive.
Earth pone they stronk, have apples, can use tech, the backbone of society. The Earth pony culture is the least likely to implode, thus indoctrination and turning the young (random pony babies from Earth pony parents, inti their own).
Chungus horny wing ponies… individually kinda okay for a direct confrontation. While they could do a scorched earth policy they can't keep it up forever. Also has all the stuffs. Considering that all alicorns so far are female, they need to get the seed to breed (assuming they can). Basically spawn as many uber pones as possible. Unlikely to win vs everyone else. Unless there is friendship and magic or some bs like that.
The grabbag of horrors, and Spike. It all comes down to numbers and how good ensuring saftey. The monsters and huge animals are tough and dumb to an extent. Dorguns can fly, breath fire, are immune to lava, and can grow immensely. They just don't care units they can get something. Griffs they have… uhh… talons, and wings. Both don't friendship good. ZI- I mean Zebras' are rare in Equestria, potions for every occasion. Buffalo does what a buffalow wants. Windegos, race war means good eats nom nom freeze them all. The various side characters could pose a problem. Discord wins this engagement before becoming bored. Changlings can zerg rush. Hippyfaggot Changlings create energy ex nilo by sharing it with each other. Put them into a giant hamster wheel and watch the infinite power in motion. Mirror Magic, temporary means of everhthing has gone to shit. Excaping the mirror is easier than craming eveeyone important inside.