So it appears that the original tusken raider revives, and the summon is resummoned while another tusken ally is active. So if you use a character that prevents revives, you need to make sure to kill the original Tusken Raider, then kill all other tusken allies, then finally the summoned Tusken Raider to kill them all dead.
I haven’t checked it out, but I know in fleet battles, you can see which vulture droid on a Grievous fleet is a summon by clicking and holding down on the unit. In the info box that pops up, it will say “summon” in the corner. I bet this is also the case for the Tuskens, but like I said, I haven’t checked to confirm this.