Do you plan to invest heavily in trading? Craft ammo?
My last build was LMGs and it's ridiculous how fast these things chew through your ammo. I wouldn't want to play LMGs/miniguns without Mercantile, that's for sure.
Closer to the end of the playthrough I just gave up and started refreshing merchants with cheat engine lmao.
Crafting is handy if you go for something like 9mm acid or .44 explosives, W2C is always a must and if you have an additional way to obtain them that's great. But then again I got so tired that I threw crafting out of the window and started abusing cheat engine which is one of the reasons why cheat engine is evil and should not be used normally: it destroys game's design.