Yes, there is some confusing evidence on Hawk Man. According to Decost Smith, he was indeed Long Soldier's son; this is also supported by a ledger book which has multiple drawing of Hawk Man, Sitting Bear, Feather Earring (Dog With Horn's brother), and His Fight/Jaw, all from the same extended family. Yet, interestingly, Smith states that Hawk Man lived well into the reservation period, so could not have been killed at the LBH according to that... So the two might possibly be different individuals. And to make it even more confusing, there seemed to have been yet another Hawk Man, an Itazipco, who died at the LBH; he might be the same as the Hunkpapa Hawk Man I mentioned above though. Would be good to understand more on the Hawk Man family or families.
If that’s Long Soldier’s son (according to Smith he was) then the Hawk Man killed at the LBH is obviously another man. Will check my notes who the source was that the one killed at the LBH is the son of Long Soldier and will post here.
Source: "A Lakota War Book from the Little Bighorn", Castle McLaughlin. Hawk Man had two pages listed in the index, as if it's one person, but having read it again just now, that might be a mistake by the editors...?
Josephine Waggoner writes in Witness, that Long Soldier was the "fiercest of the hostiles" at Standing Rock, and once threatened to throw Major Hughes, the Indian Agent into the river when he withheld annunities (p. 61).The cavalry came to the rescue. His band of eleven families, 54 people (as noted above, in the 1881 Sitting Bull Surrender Census) camped near One Mile Creek, about a mile from Ft. Yates. It was originally called Long Soldier Creek.