Bio:

“Millionaire playmare Rainbow Dash was given her late father’s salary and technology. She used the latter to sell weapons to the Equestrian military. Unfortunately, Rainbow caught a piece of shrapnel in her heart from an explosion (but unintentionally survived) and was taken hostage by dreaded terrorists who wanted her to build weapons in their own image. She built an armored suit with the help of another prisoner of war named Spotlight, whom died helping her successfully escape. Upon returning to New Ponyville in Equestria, Rainbow decided to build an improved version of her first armor and became the metal heroine known as Iron Mare. With the aid of her artificial intelligence assistant J.A.R.V.I.S., she fought off terrorism across the land. Her business rival, Suri Polomare grew increasingly jealous of this “Iron Mare.” Thinking Dash has gone too far, Suri built her own armor, the Crimson Dynamare, and used it to combat the iron pony but ultimately lost the battle and vowed to return. Upon hearing that Fluttershy, AKA Captain Equestria, was found and thawed out by the Apple Family, Rainbow greeted the first Avenger in a rather friendly manner. After aiding Spike (Spider-Dragon) in taming Hulklight, the heroes were also joined by Pinkie Thor, Applejack (Hawkeye), Rarity (Black Widow) and Rainbow’s best friend and Twilight Sparkle’s older brother, Shining Armor AKA the War Machine.”

Can Shining Armor be War Machine if Fluttershy is Captain America?

Fluttershy would’ve been War Machine

Nice!

she is the iron pony.

Girl.