Another quick thought

When the shop didn't have a black tourmaline egg, Percival didn't choose tumbled pieces, or a sphere. He then gravitated to a wand. At the time I didn't think much of it, but now...think about it.

Black tourmaline offers protection and helps manage fear, right?

And Grindelwald stole his wand, right?

So of course he'd gravitate to it. It's incredibly symbolic. His wand couldn't save him the first time.