Exactly, there are several subclasses. for example USS Duluth featured a square bridge, and the location of the 127's was changed several times... that being sais.. i have been collecting sources on the different cleveland sub classes.. so dont exnay them just yet.
Actually every Cleveland after CL-64 USS Vincennes featured a square, or "open" bridge. But from what I can tell from the research I've put in to it (I'm building a model of the Miami... Takes lots of time staring at pictures to find the exact perfect spot where the 2nd door on the 2 deck on the port side of the aft superstructure goes) the 5in turret placements didn't change all that much except between the round bridge and square bridge builds. The superstructure also did change slightly (aside from the bridge shapes) during the round-square bridge change. Mostly above the level below the bridge deck is where the most change was from what I've seen. The Mk 34 and Mk 37 director placements changed many times between ships sometimes with the Mk 34 main battery director being above the Mk 37 5 inch director and sometimes it was the opposite. I know the outfit of 20mms and the number of quad and dual 40mms changed constantly in the earlier Clevelands the area between the stacks was the boat deck but that was later deleted to reduce top weight and instead the design was changed to two sets of boat davits on the sides with whale boats suspended. The lack of boats was supplemented by the addition of many, many rafts in many places (under the catapult, hanging from the railings, where the boat deck was, etc). The type of crane used changed constantly between ships as did the location of floater net baskets. On the boat deck equipped ships, a midships crane was used. This was later deleted when the boat deck was phased out. The radar fit was constantly changed as well between ships. Although this had more to do with upgrades and what radar was being used at the time. Earlier ships sometimes used the SC-2. The majority are seen with the large SK array and towards the end of the war and after the circular SK-2 was seen. Extending from the main masts were two smaller masts which usually held SG radar antennas on top.
I'm not doubting you. I know there were many changes between ships but in general this is what I've found as an amateur researcher doing research for an intensive and relatively accurate build.