Warren Buffett is both. He's a very capable schmoozer now after decades of practice (he wasn't when he was very young). His style of schmoozing, the disarming folksy charm etc., is a huge part of what enabled him to buy the companies he did, luring in very talented owner/operators. And he's an empire builder of the scale few in world history have ever managed in financial terms. To manage to put something like Berkshire together and not have it collapse under its own weight after 50+ years (due to mismanagement or any number of dozens of common reasons), is an extraordinary accomplishment of building.