Fury = The Doctor: Both look after their bands of misfits, and defend the Earth.
Tony = Jack: International/intergalactic playboys willing to die for the greater good. Many times over in Jack’s case.
Steve = Martha: Underdogs who became heroes, fighting tyrants for freedom and justice.
Bruce = Donna: Both forced to embrace a personality they didn’t want. The only difference is, Donna no longer remembers what it was like to be fully her.
Natasha = Amy: Both badass redheads with pasts they tend to run from.
Clint = Rory: Soldier types who always come as a package deal with their badass redhead.
Phil = Mickey: Both The Man In Havana, both eventually drawn to Big Fucking Guns.
Maria = River: The capable second-in-command.
Thor = Rose: Both channel godlike powers (that they had to prove themselves worthy of.) Also, both blonde.
Loki = The Master: These two would get on like a house on fire…no survivors.