Adorkableness levels reaching critical!
 
@Background Pony #B7B1  
@Yet_One_More_Idiot  
I personally was always fine with them being unconnected, and would probably do a crossover by “someone got their hands on a dimension-jumping spell/doohickey.” But, just for fun….
 
G3 and Tales take place earlier. Around the same time but in different places with different levels of tech. More Earthlike technology is used by earth ponies that have not had much contact with the other races. G1 exists between that era and the FIM era, in a zone like the Everfree Forest where nature more or less runs itself and the danger is greater. (In fact, it could be the actual Everfree Forest, if the Everfree is big enough. The outside world doesn’t know the Dream Valley civilization exists because they’re too afraid to venture deep enough within. Far on the other side of it dwell the races FIM doesn’t seem to have.
 
Exactly when to set it depends on how you want to do the “ancestor” thing. If we can’t have two descendants of the G3 Apples (Applejack and Apple Spice were background ponies, Apple Spice more prominent; the toyline gives us Candy Apple and Green Apple) that happen to be named Applejack and look a lot alike, then however many years you want can separate them.
 
However, the FIM cast outside Applejack looks quite different from their G1 counterparts, and both series have ponies with the same name. If Cloudchaser and Cloud Chaser can live in the same city, and the same family can have a Golden Delicious and a Goldie Delicious, then there’s definitely room in the whole world for Twilight Sparkle and Twilight. If their families kept good records then maybe they’ll find Twilight Twinkle is their ancestor.
 
Also, if they do take place at the same time, the closest matches can be the same pony. Maybe Surprise moved to Equestria at some point. Maybe Applejack didn’t only go to Manehattan while trying to find herself.
 
Firehooves’ fanfic series has it that FIM is the earliest, Tales is in an area with less magic, G3 is a future Ponyville where some ponies are named after their FIM ancestors, and G1 is post-apocalyptic, after an epic pony war wrecked the previous civilizations. Also, Applejack is immortal and all Applejacks and a few other Apple-named characters are her.

@Background Pony #B7B1  
I think that way too, although I find it hard to reconcile the fact that G1 has magic, unicorns and pegasi, but G1 Tales doesn’t have those things, and then G3 has the Earth ponies discovering the unicorns and pegasi, and then in G4 they all live together and have for centuries.
 
Would you chronologically order the series in the order they were made? Or would they maybe make more sense in some other order?

I always considered the previous generations of ponies to be ancestors of a sort

stfu@Spiritus Arcane

NEERRRRRRRDDDDDS!

Brainiacs from across time and space…unite!