The ice-bound Centurion mentioned in the name, is actually a group bosses from the nearby area.
The area the skyshard overlooks is just south from the group boss. If you are at the start of the boss’s pit, look toward your right. There is a stone structure, just on top of a smaller hill. Climb it and go inside the structure. Almost at the center of it, just next to some trees, on the ground is the shard. I don’t think you can hit the boss from a nearby platform, but why bother when there is a nice field down into the pit where you can die from the Centurion if that is your fancy.
Sand Kingdom Moons - Super Mario Odyssey Power Moons