"Andrews would've been a continually annoying obstacle. Had someone else been got in the mess hall and Andrews lived, he still would've tried to assert his authority in combatting the Alien instead of deferring to Ripley. Clemens probably would've been Hicks Mark II."
Andrews definitely would've been a liability. His death was necessary for Ripley to be able to assume a leadership position, although it might be arguable that the position she took was more of a proxy through Dillon, who held the others in check and gave much needed pushes when required.
While clemen's was a great character, his relationship with Ripley may have provided an unnecessary level of human interest at times when survival needed to take center stage. His death also was a stout twist of the blade for Ripley, as the last chance of her having any kind of close personal relationship with another human was taken. Whether this mentally played even a small role in her decision to end it all or not, it sure must have been one of the last "little" nails in the coffin.
As far as Hicks 2 goes, I think Dillon really takes that cake. Dillon was a good parallel to Ripley, though his troubles were probably of his own making, he was a strong leader and intelligent individual who chose to fight rather than die. It's funny, sometimes when people think about the Alien movies, they think of the strong female leads. But I think it's fair to say that Parker, Hicks and Dillon had very strong Male roles in each of the films.
I will add though, that like Parker and Dillon, Hicks should've been allowed to go down fighting. However, with the script for Alien being what it was, he would've spent that film trying to protect Ripley from the inmates and the Alien, and it would have added too much drama. I have a feeling we would've been looking at Hicks making good on that "I'll do us both" promise near the end of Alien 3.