Perhaps not the style of any he is accused of -- at this time. Sandra Costilla is also different.
"chasing after a terrified prostitute running through the marshland in the dark" That was an extreme situation that perhaps called for extreme measures. Plus, we don't know she ran into the marshland, do we? SG's remains weren't found for a year and a half. I don't see any way of knowing when her body went into the marsh. RH was an avid hunter. I don't claim to know what happened to SG, but I don't rule RH out.
RH seems to have enjoyed scaring women. Remember the woman from his office he sent a note to on a boat in the middle of the Atlantic Ocean telling her he could find her anywhere?
Remember the affidavit from the woman who attended a swinging evening at the Heuermann home with her policeman boyfriend/partner? According to her story, as I recall, she remembers leaving a tiny, naked woman who appeared to be scared? While I'm not convinced the young woman was Karen Vergata, I think that evening and that frightened young face has probably haunted her for years. The boyfriend said the young woman was ok, Rex was playing a game with her, remember?
Yes, as you suggest, RH did like taking his time and the power of holding them captive - at least the ones he is charged with, so far. But he also appears to have enjoyed the power of instilling fear, of making people aware of his ability to find them, to play games that displayed his intelligence.
Unless RH decides to talk sometime in the distant future, I seriously doubt the extent of his crimes will ever be known. I hope his pride and need for the world to know his "accomplishments" will eventually lead to him discussing his crimes -- perhaps after a few convictions and with nothing left to lose. When there are no more games to play, will he want to hold long post-mortem discussions of the "games" and his brilliance?