The Mech Rhinos will attach to the ends of the assembly.  The four Mech drawings are the larger 28 1/2" x 22 1/2" pieces.  There are two drawings with two Mechs and two with just one.  Their order in the time line is pretty well set by the construction order of the domes behind them.  The only one that doesn't have a dome, is Tyrian Raptor & Psychedelic Phoenix.  They are somewhere in the old City.