I’m afraid you have it a bit jumbled.
LaFayette came to Philly and was handed a commission c. Summer ‘77.
Basically, Brandywine and Germantown led to Congress leaving Philly and heading for York (Sept/Oct ‘77). (LaFayette was first in combat at Brandywine.)
During the Philly campaign, the Saratoga campaign was also playing out, headed by Horatio Gates.
After the Saratoga campaign and surrender (Oct ‘77), AND partly due to the news of the good fights put up during the Philly campaign (is was NOT all due to Saratoga), France agreed to help.
After that as well (Fall/Winter ‘77 on), Gates as well as others were involved in the Conway Cabal, hoping to place Gates in command over Washington.
I said nothing about where or when Lafayette received his commission; nor were my remarks presented as a chronological history of the Revolution.
Lafayette came to York, PA, the first Capitol of the United States, and his toast to Gen. Washington let the air out of the cabal. Period. And thank you.