I don't need any proof that Patton may have said it, as it sounds enough like something he might have said to be plausible and I don't intend to quote him. I do doubt that he had the "clinical expertise" to diagnose amphetamine's effect on what looks ghastly.
They may have been just ghostly pale because crashing in a glider scared the s...t out of them???? A friend who claimed to have flown one of the last half-dozen gliders into Bastogne said you could tell the ones who "glided in" by the expression on their face a week later. And he made a "safe" landing.
There's ample evidence of "stimulant" use by all sides in recent combats; but of course "we only do it when necessary, but they're all real dopeheads" was probably a standard propaganda line.