However, Arnold was not at Lexington, nor was Lexington "the decisive victory that won the war."
Arnold fought valiantly and was wounded at Saratoga which, arguably, was the turning point of the war but certainly not "the decisive victory that won the war". After failing to gain the credit he believed he deserved, and probably did, for that battle he turned traitor.
No one would argue that the Congress, or Washington for that matter, treated Arnold fairly. That doesn't mitigate the fact that he was an egotistical, self-aggrandizing jerk who turned coat and actually led British troops against Continental units before fleeing to England where, by the way, he was largely shunned.
You're right. It was Saratoga where Arnold saved the day, captured a British Amry ... and thereby saved the Union.
I'm getting old, and forgetful.
But good memories abound in my mind. I've been a very lucky guy.