Fantastic Antagonists and Where to Boost Them (w/apologies to JK Rowling)

With the recent release of Allies & Adversaries, I've been looking over it and a question popped into my head. While the book is full of useful profiles for campaigns of various types of generic types that appear in the Galaxy FFA, a handful are unique profiles of some of the most in/famous characters there. There's just one problem.

How do you make them tougher? This question arose in the process of sitting down to write out a campaign that would have the PCs encounter at least one of the ESB bounty hunters as a recurring antagonist. (Or, should this happen outside the time of the Rebellion, that time's equivalent.) Increasing skills is one thing, as there's an easy way to do that, and increasing stats, while not following with how PCs gain stats, there is at least a means by which to do that.

But non-PC profiles, while they have Talents, don't have access to Specializations and thus trees to use to purchase new ones...suggestions about how I could handle this?