No, you also need to ask not just whether they're similar, but whether they are the way they are for the same reason, and are thus likely to change together. I

No, you also need to ask not just whether they're similar, but whether they are the way they are for the same reason, and are thus likely to change together. It doesn't matter if there are 10, if they all might change independently in arbitrary ways. "DRY" as coined in The Pragmatic Programmer spoke in terms of pieces of knowledge. If you are combining code just because it looks similar, you're "Huffman coding."