[rdonj]

I'm going to go on the record as saying that I don't really think units look too much like each other. There is the rare unit that looks almost identical to another unit almost exactly like it, but as others have said these rare units are basically interchangeable. But for the most part, even similar units are sufficiently different-looking so as not to be too hard to tell apart. And I say this as someone who would not be physically capable of reading a thing on their screen without glasses.