Isn't tabarruk equivalent to believing in amulets and talismans?

Can anyone please help me with this? It's been frying my brain like an egg for some time. There are reports of the companions taking relics of the Prophet SAW in order to get *blessings*. A report regarding Khalid ibn Walid RA can be found where he used the hairs of the Prophet SAW and remained victorious in every ghazwa. HOW IS THIS DIFFERENT FROM BELIEVING IN AMULETS & TALISMANS? HOW IS THIS DIFFERENT FROM THE EVENT OF DHAAT ANWAAT? Indeed there are authentic reports where believing in such things is shirk. Isn't this a theological contradiction?