Ken,
I saw this Osage Indian Battle posting and see and have read, in Battle they cut the head off the
enemy-so that the flow of a sprit-cannot harm them in after life, and they are truely dead.
(Old-Custom)

I have one Confed account of a Osage at Locust Grove by a Judge Potts -of some 80 Osage's for scouting duties;poorly armed,Lances,Tomahawk's,etc.but fine horse-men they were then to make a break away as part of the 80 when the Fed's moved in to Capture the Confed.
In this small conflict was a number of horse's running in open type fields both sides/Confed/Fed's
In his story he said one of the Osage neared the Fed leeped from his horse,with a Tomahawk in hand cut his head off- both horses went down and he stood with the head of the Fed on a lance got back on his horse held it high for the chief to see,the chief give him a thumbs down, and he dropped by the body and rode back to the chief.(my summory)

Likely the events of Desertion,surrender at Lucust Grove made this a minor thing in this battle
I sent this to David some years ago --Clarkson book he did not use it.
(He stated that 80 Osage Indian were said to be there.)