I can whip this ragtag crew into shape pretty quickly.

The ragtag band impressed all who were present.

One definition is: A ragtag army is a disreputable or disorganized group.

There is no anagram. The letters can spell "this gag arm" or "ragtag shim."

I assume the phrase refers to the Colonial army. As the war progressed the army became better trained and somewhat better equipped, but perhaps "ragtag" still applied. They were certainly a band of rebels.

1. His novel is a ragtag, piecemeal work.