Well, anything is possible but it doesn't seem like Kuklinski really had that much contact with connected guys. Why would Sammy hire Kuklinski, who claims he was paid upwards of 50,000 / hit, when he could get someone he knows and trusts for free?

There's pretty good reason to cast doubt on anything Richard kuklinski claimed about being a hired hitman. No doubt he was a sociopath and a murderer, but he's also a pathological liar. He's claimed to have been responsible for the Galante, Castellano, DeMeo and Hoffa hits, too.