I bet there has been a ton of business conducted between Kaido and Big Mom...whether it’s directly between the two or through their emissaries in the Underworld, they’ve absolutely swapped weapons/potentially Devil Fruits as well.
However, in my opinion, Whitebeard/Shanks/Blackbeard wouldn’t or didn’t engage in this kind of thing - Whitebeard because he felt confident enough in his own abilities and could act as he pleased; Shanks because he’s all about diplomacy (or is funded by the WG?); Blackbeard because of his hubris/desire to take what he wants rather than negotiate.