We can't assume there are two William Cashmans from the same section of NJ since we don't know Hawkeye's name. Two people from NJ in the 101st in the 60's is very probable. Remember one was from May 1969 and the William Cashman article says he was a paratrooper in the early 60's.
I did a little checking from Hawkeye OT posts and I was hoping to find something personal that would corroborate or refute what is known about William Cashman. It seems William Cashman had at least two sisters from this link
Here
From a post that HawkeyeNJ made, which he told a story about himself (he said it was true), he only had one sister (which he didn't name). Read the post by him or the whole thread for that matter. He's about 2/3'rds of the way down
Here
Here is a partial quote from Hawkeye from the thread: "... I YELLED OUT "WELL LET ME TELL YOU SIS ! " Her friends: One friend tried 2 get between us. Then in a normal voice I continue. " I can replace the fiberglass and metal get another car. That I can do. But I have only one sis and I can not replace u ! As long as u r fine things r fine with me. Now forget about the car."
Also further down his post he mentions that he went or was going through chemotherapy.
"Take some advice from some of us old farts. I wished I had @ your age. Old farts back then told me not to smoke but like u I was smarter then them. They just p*ss*d me off. @ my first chemo treatment I remembered their words. Dam those old farts were pretty smart ! "
I dunno, draw your own conclusions. I don't think HawkeyeNJ is William Cashman.