The solar arrays used on the ISS were launched in 4 different launches. Starting in 2000 for the first array, used on the Z-0 truss, to 2007, 2008, and 2009 for the final three.
Are all 4 of them identical in design? Therefore the question, were they manufactured as a set?
Or did the first array go up, and based on its experience in orbit and new solar cell technology contribute to a modernized design for the next three?