They're nearly identical at knees and waist but Tatum's shoulders are a good 2" higher than Karaban and Tatum is about 2" taller than Karaban.
I was referring to how UConn lists the players, the quoted post was talking about that. Not the comparison between Tatum and Karaban.
UConn lists players height w/ shoes. It's pretty clear looking at combine measurements this past year where they only took measurements without shoes:
Newton w/o shoes 6'3.5 - listed by UConn at 6'5
Sanogo w/o shoes 6'7.25 listed by UConn at 6'9
Hawkins w/o shoes 6'4.25 listed by UConn at 6'5
Jackson w/o shoes 6'5.5 listed by UConn at 6'6
Sanogo's was the only real question mark.
For reference 1 to 1.5 inches is pretty normal to tack on for a w/ shoe height.
Martin w/o shoes 6'5.5 listed by UConn at 6'6 (with shoes at Gleague event 6'6.75)
Bouknight w/o shoes 6'3.5 listed by UConn at 6'5 (with shoes at combine 6'4.5)
Karaban is listed at 6'8 on the UConn website, it would seem he's closer to 6'6.5 or so based on how UConn usually lists heights. Tatum didn't participate in combine results so it's unclear if his listed 6'8 is with or without shoes. I would guess without. There are reports of him being 6'7.25, or 6'7.5 without shoes but the ones I found looked unreliable and/or when he was still in high school.