If things needs to evolve to separate direction, you can duplicate them. Unreasonable X is unreasonable, that's true no matter X but that's not very insightful

If things needs to evolve to separate direction, you can duplicate them. Unreasonable X is unreasonable, that's true no matter X but that's not very insightful. Unreasonable factorizing is unreasonable. So are unreasonable copy pasts. Now a good question can be: would I "prefer" one or the other gone too far? That's merely a personal preference question, and on my side I've got a clear answer: I prefer something a little bit too abstract, to something a little bit too copy pasted. Because while abstract I still can understand more of the system more quickly, whereas duplicated I basically have to start by reading a lot more and factorizing (possibly in my head) before getting to a balanced situation... Your own preference may vary, but I've yet to see a system maintained correctly by people copy pasting too much and not caring about anything but the one example they have to handle (because e.g. of a workflow described in a ticket). Things can be accidentally similar, but WAY more often in copy pasted code-bases they are accidentally diverging, and that multiply the time I spend on that kind of mess by a factor that is probably near 10.