If the Fuher of Equestria ruled for a time it would be solution solving. Equestria is for ponies...
However Equestria has different challenges than Earth. Putting it another way Adolf Hitler would be an honorary Pony and of many other 'races'/'species' because of the unique perspective humans and a leader from dark times to brighter times to even darker times have.
A more desolate differently hostile world than their own.
It's more that each area is for each of the different beings that inhabit the world. That's not to say trade wouldn't exist it would, but the cross multiculturalism would be resisted in a way other nations form a genuine brotherhood of friendship.
Ponies tend to hyper focus within the scope of their cutiemark.
Crystal Ponies are see through.
Dragons swing between 'tarded and empowered by gibbs me dat.
Griffons tends toward being a bitter people. Once they learn about labor backed currency, how improvements to each other and the surroundings is actually enriching and friendship they would be a fast friend.Assuming not like the (((ones))) kicked out of over a hundred countries.
Nu-lings apparently don't require anything to survive so I suppose they can star in exploration or something.
Changlings are like less sneaky (((assholes)))
Kerin are an emotional flamenwaffen only bulli for a sizzle.>No Hooves
are almost human and probably don't have (((them))).
Diamomd Dogs are a slaver nation and a solution needs to be found.
The Furries are a clusterfuck.
Villains of the week happen to be a world wide issue.
Spork the Dragon would be a national defense asset and liability but mostly asset. As documenting dragons is important so is having one on hand. Tentative pass for being there before any law is introduced and technically a multinational hero. And for being a dragon more mature than other dragons in his age group... technically... sort of.
Also would make some ponies sad.