Like the other poster said, Leo came up much later.

I don't know. It seems like River's peers that went on to be A list actors did so with big box office hits. Whereas if you look at Jaquin Phoenix, it seems like he largely shows up in smaller films, and only occasionally shows up in the big movies. Even guys like Ethan Hawke probably only made it because every now and then he'll do a couple big movies to pay the rent so that he can afford to take a pay cut with the smaller films that he probably prefers doing.

So I don't know. I can't picture him going action hero but it seems like that might have been he's best shot at sticking around.