Wandering Trader spawns with 2 wandering trader llamas and 2 regular llamas

are they hooked up to a lead? if not, then it must be that the normal Llamas must have detected the trader Llamas and started following.

The regular llamas did not spawn with the wandering trader, they spawned with the mountains biome. When the trader and trader llamas showed up, the llamas want to follow the leaded trader llamas which is also intended.

That must have been it since i'm in a mountain biome. Do the traders spawn a decent ways away from you and run to you?

Wandering traders will spawn up to 48 blocks away from you, as I recall it said on the minecraft wiki. They could spawn a bit far away but there's nothing stopping them from spawning next to you as well in my experience.