>>83726975>Steve's probably physically the same age as Evans
Evans is 4 years older than Cap.
RDJ is 5 years older than Iron Man.
Cheadle is 4 years older than War Machine.
Stan is 4 years older than Bucky. (Fun fact according to the wiki and google, while Bucky was born before Steve, he got frozen first so Cap is about a year older physically minus Winter Soldier missions).
If Peter Parker is 16 then Holland is 4 years older than Spider-Man.
Sam Jackson is 3 years older than Nick Fury.
Pratt is a year older than Star-Lord.
Ant-Man's age isn't given so eh.
Clark Gregg is 3 years older than Coulson.
So really it's only BW, Hawkeye, Falcon, and Maria Hill that are the same age as their actors and "most" are not. When they're not, the character is usually 4 (but up to 5) years younger than the actor. And 4 to 5 years a pretty big gap when you're in your 20s.
So for the MCU, you're wrong about cast ages. Now that does not prove SW is not 27, but it means there's no strong evidence to support that either.
But here's a bigger issue with your "use the actor's age" idea, Quicksilver's actor is 25. Can't have the twins be twins with a two year age gap.