Each of the Mane Six has characters to interact with. Rarity might have a more avant garde edgy designer assistant who takes more risks than Rarity. Or Fluttershy writes letters to a Steve Irwin like person hoping to meet them one day.
Being my AU is probably to be read by teens and young adults since it is on fimfiction, I can focus even more on each of the Mane Six's jobs.
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Also more focus on politics and the struggle between the different pony races. The pegasi ans earth ponies are jealous of the unicorns. And there is a constant subtle tension between the three races. The dragons are more complex and while brutal also sophisticated and the Mane Six will help to rebuild the formerly glorious dragon civilization.