he Rephaim giants (specifically the anakites) are exaggerated in Numbers 13:33 (we looked like grasshoppers to 'em!)and it wouldn't take much size to be considered a "giant" in those days (average hebrew height was around 5'3-5'7) A race of people as tall and a large as a football lineman (6 feet 4 inch, 305 lbs) would seem quite gigantic to the tiny hebrews.
I'm not sure they where talking about height though, but streight verses weakness, i'm thinking its like we say swatting you like a gnat, its not that you are like a gnat but that you are as easy as one
I dont think the Bible's original autographs exaggerated Goliath's height, though whether it rendered 9 feet or 6 '6 feet is up in question. Either way he was a big sun-of-a-gun who not even the giant saul wanted to mess with. Only a little teenager with a slingshot (effective weapon) took 'em on, and nailed that sucker right in the forehead LOL.
yes they would do that to make it a better more exagerated story to make david greater than he was, most likely goliath was at most 6 foot, that still would be tall - i watched the history channel about david and his sling shot, seems it was a pretty powerful weapon if used right
smacking goliath in the right spot in the forehead would kill him, if the right force is applied