I can understand and sympathize with why they would want to kill the assassins -- to save their own lives -- but at the moment I don't understand and sympathize with why they want to smuggle the money.
Speaking for myself, I am not interested in heist movies where the protagonist is in it only for the money. The operative word is "only". I have no problem with a protagonist wanting the money, but I do have a problem if he's stealing or smuggling or whatever for no other reason than sheer greed. Consider "Ocean's 11": The reason Danny Ocean selects the 3 casinos to rob is that the owner, Terry Benedict, has 'acquired' his ex-wife, Tess; he still loves her and wants her back. A pivotal player in the plot, Ruben Tishkoff, wants revenge for Terry forcing him to sell out his casino -- and then demolishing it. The two are not in it just for the money.
So why does your protagonist want to smuggle $100,000,000? To Cuba, no less.