I agree about Vulture being a non-factor for the most part. A number of things in Batman's arsenal could neutralize the old man.
But I wouldn't go so far as to compare Sandman to Clayface. Batman is through and through, a street level hero, when it comes to chance encounters. Without prep time, specialized gadgets, customized exoskeletons, ect, he doesn't have the tools to put down Sandman.
What would Batman do against 150 Sandmen? Or just one Sandman 150 feet tall? Yes, Bats has experience dealing with shape shifters that weaponize their own bodies. Clayface to me represents one of Batman's most tricky and dangerous villains. Unlike the Joker or Riddler, the brute physicality and versatile intrinsic armory of the Clayface represent an imminent threat. Now imagine that we gave Clayface access to potentially nigh limitless mass, and the ability to direct said mass with precision and power--remotely, mind you... I think Sandman solos a comfortable 90 percent of the time.