@Twi Clown  
The first line is unused anyway so…

@Moon Flower
 
Amazing kamerade.
 
Plus, while this to some degree affect any match up under normal circumstances, trying to make a crossover while keeping some degree of character, Medic’s sense of humor would be very VERY hard to adapt to Flutter’s character.
 
“Did ze Fräuleins have zeir Mittelschmerz?” Too crude for anypony in a 100% in character, but even adapting the personalities would make it hard for fluttershy
 
“Standing near ze point does nussing. Get on ze point, Dummkopf!” Twilight would be able to call out in a more or less rude manner to her companions especially in season 1, not Flutters.
 
“Eins, zwei, drei… Ugh, I do not think ve brought enough body bags.” This one can work with Twilight’s OCD tendencies: she never expected so many corpses in the battlefield and she feels unprepared.

I agree with many arguments in that long debate, I just wanted to throw in some more.
 
First the silly one.  
Twilight Sparkle in PONY.MOV pretty much nails it. :D
 
As the medic says himself, the healing process is just a positive side-effect, he doesn’t even really care much as long as he makes any progress in his experiments.  
The kind of madness fits best to Twilight regarding the Mane 6.  
Pretty much like Twilight learning friendship lessons no matter what.  
(Later this role is filled by Starlight. Though it still is Twilight who’s insisting on the lessons, hehe.)
 
I found Fluttershy as medic lovely, but that was before I learned about the medic’s nature, motives and character.  
It makes not much sense to connect that to Fluttershy.
 
Also Fluttershy cares about critters, non-sapient animals.  
She would fit as a veterinarian, but not as medic for humans - respectively ponies.

@Twi_Clown  
Well, moreso than Fluttershy anyway, who has no drive to experiment and is about the furthest thing from a Frankensteinian mad doctor you can get. Fluttershy’s not the character you’d expect to find in a laboratory, performing bizarre, arcane experiments on her teammates, or harnessing a little-understood formula to magically heal her friends and render them (and herself) invulnerable. Any situation where Twilight is less scientifically inclined than the local farmer and animal caretaker just feels wrong on a fundamental level.

@Background Pony #1FB0
 
I can also imagine Twilight with her social incomtence in a darker set would say to Big Mac in the operation table that once she dissapeared the skeleton from another patient and that she lost her medical license.

@Twi_Clown  
I agree, and on that point, Twilight’s magic and intellect are what really sets her apart. Twilight’s not just ‘really good at math’ smart, she’s ‘breaks the laws of time and space’ smart – which is part of why this picture fits so well. I mean between Medic and Sniper, which seems more likely to change the diets of animals, or brainwash his teammates into obsessing over a stuffed toy, or discover the secret to time travel? That sort of stuff is beyond the Sniper’s scope (pun intended), but looks like the kind of stuff the Medic would try to do just to see if he could.

@Background Pony #1FB0
 
He did it for a relatively noble (for a loose definition in medic’s case) reason: that way Demoman wouldn’t remember how many times medic has failed saving his eye. (Well, it was because he didn’t wanted to be bothered by questions like “Where’s my eye? Where’s my eye?” but one can argue it was for the best.)
 
It actually sounds like something Twilight would do, given her tendency to try to resolve issues with magic at times.

@Twi_Clown  
I wouldn’t say the Medic is ‘antinaturalistic’, so much as I’d say he’s not overly concerned with the well-being of animals, especially when their organs might be useful in experiments that human organs simply cannot survive. It’s more like severe indifference. I mean this is the guy who surgically removed a piece of the Demoman’s brain to make him stop asking him to regenerate his lost eye (which the Medic says is actually a fairly simple procedure).

@Background Pony #1FB0
 
Not to mention the animalistic thing.
 
Medic has experimented with baboon uteruses, blue whale’s whatever that purple thing was (I’m not good at remembering terms or some things as you can tell) and so on. Medic is fairly antinaturalistic, going against Flutters’ quirks.

@Twi_Clown
 
Actually, Healers aren’t really stereotypically shy or meek. The usual stereotype for a healer is that they are caring and nurturing, to help emphasize their nature as a caretaker.
 
I personally don’t have a problem with Fluttershy being sadistic, especially bearing in mind that none of the Mane 6 are exactly violent or murderous, I just find it silly considering that making Fluttershy the Medic to emphasize her kindness contradicts the spirit of the Medic himself, while making Fluttershy psychotic defeats the very purpose of the match. It becomes especially offputting when you realize the match literally turns Fluttershy into the genius who runs experiments and makes scientific discoveries, while making Twilight the furthest thing from it.

@Background Pony #1FB0
 
Healers are usually portrayed as shy, often meek, reserved and not very aggresive most of the time. Is a stereotype that while I understand the reasons, I don’t think it should go always that way, specially when you can make far more entertaining characters in another way.
 
Have been Mercy from Overwatch, generic White mage from RPG or Yuna from Final Fantasy X qualify for the crossover personality wise among the healers, Mr. Ludwig from TF2 is a maniac with no regard for human life, highly extroverted, non-animal lover outside of his pet doves (He has baboon uteruses for crying out loud), is definitely not less sadistic than his peers and has a Mad scientist mentality. Would you say that Fluttershy could fit in the basic model for TF2 medic?

@Twi_Clown  
It’s not so much about similarities, it’s mostly fans always making Fluttershy the healer, and because Twilight’s shtick is being smart and the two smartest classes - being a healer and a southerner - were already taken, so she was sort of put in whatever was leftover when the other characters were sorted out.

@Background Pony #1FB0
 
Is kinda sad that the artist metal-kitty often get shit thrown at hit just because he has another setup for the crossover, one that greatly influenced my decision to think twi is better medic than sniper.
 
I wish I could know why the twi-sniper flutter-medic setups, because I still can’t see the similitudes.

@Twi_Clown  
I never got the Sniper. I mean I understood the argument that snipers need to know some math, but being smart enough to shoot a guy five miles away is nothing compared to being smart enough to put a baboon heart in someone and fix a device to it that makes the recipient invincible after applying an electrical charge. Of all the mercs, the Medic’s abilities most resemble Equestrian magic, after all.

I like the crossing between Medic and Twilight. In fact, I think it fits better with the “Mad scientist” schick than Sniper.

I do enjoy the Medic’s Doctor Who stuff, perfect for him! Great work!
 
Also, Twi Medic is best Medic!