It seemed Talos could do a lot of stuff at once, and heroes from previous gamesmay have done similiar things.

I'm aware of the Talos/Wulfharth/Arctus Oversoul thing but I've heard it's made up

It's not made up. Hjalti, Zurin, and Wulfharth are an enantiomorph that together make up the god Talos.

The reports of him appearing in multiple places at once are because no one can tell Hjalti apart from Wulf. (Because they became the same entity)