Hmm…looking at this again, I think I’d use the descriptions from the Brady Kids cartoon series to choose the Mane 6’s positions:
 
Meet three sisters; now meet our brothers.  
Greg’s the leader and a good man for the job;  
There’s another boy by the name of Peter;  
The youngest one is Bob.
 
See our sisters, they’re all quite pretty.  
First there’s Marcia with her eyes a sparkling blue;  
Then there’s Jan the middle one who’s really groovy;  
And sister Cindy too!
 
So from there, I would arrange them as so…  
Greg = Twiley (she is the leader, like Greg)  
Peter = Dashie (energetic, a bit madcap at times, needs to be reined in by Greg, Marcia, and even Jan)  
Bobby = Shyshy (not really so much, but the only one left…and Bobby is also a bit of a follower to his older brothers)  
Marcia = Rarity (brains and beauty, like Marcia)  
Jan = AJ (exceptionally hard-working but often overlooked in favour of others who are more in-yer-face flashy)  
Cindy = Pinkie (usually very bubbly, can pop up and listen on anyone anywhere without warning!)
 
Did I just overthink this? …does it matter? :P

Hi, my name is  
Huh?  
My name is  
What?  
My name is  
Who?  
My name is  
Wicka-wicka, Spike the Dragon

Very cute! :) Though, given Jan’s flair for the melodramatic in the show, I might’ve put Rarity in her spot on the middle-left. :)

@Shepherd  
https://m.youtube.com/watch?v=WkFMMCEa5AE
 
You’re welcome.

@sumbozo
 
Link please?

@Shepherd  
Heard that in the Weird Al version. The one sung in the manner of Men Without Hats.

@naganofan99999  
Well yeah, that’s where the maid goes.

Here’s the story of a pretty pony who was banished to the moon.  
She wanted eternal night  
She was a bit of a loon
 
Here’s the story of a princes pony  
With a student all of her own  
She was sent to Ponyvile  
to not be all alone
 
Till the one night when the student met some friends  
and they saved the day  
now the fun never ends
 
The Pony bunch  
the pony bunch  
That’s they way they becae the pony bunch.

The Cutie Bunch.

I love how Spikey is right in the middle :D

The Pony bunch, the pony bunch.