That fit info is outdated and nearly worthless. The seat tube numbers meant something many years ago when all frames had horizontal TTs and most brands followed one of the two traditions for measuring the frame size center to center or center to top. These days, those values are meaningless. What you need to look at is the head tube length, with the headset to estimate the bike's vertical size.

The TT lengths are equally worthless since it requires both a TT length and a seat tube angle to define the reach. Two frames would have TT lengths of 53 and 54cm, but have the same reach and fit the same, once the saddle is moved to the same position relative to the BB. The frame with the 53cm TT could have a 74 degree STA and the 54cm could have a 73 degree STA. The result is a nearly identical reach.