Good Software Development Habits

> It's better to have some wonky parameterization than it is to have multiple implementations of nearly the same thing. Improving the parameters will be easier than to consolidate four different implementations if this situation comes up again.

Hard disagree. If you cant decompose to avoid "wonky parameters" then keep them separate. Big smell is boolean flags (avoid altogether when you can) and more than one enum parameter.

IME "heavy" function signatures are always making things harder to maintain.

Hugely agree. Every junior on my team has heard me say: "copy-paste is free; abstractions are expensive." When you move two bits of logic behind a common interface you tell the world that they're the same type of thing, and future editors will tend to maintain that promise - if the two things diverge further, someone will handle that by adding more parameters to the shared interface.

So when deciding whether to merge two similar functions, to me the question to ask yourself is "are future changes to one of these functions almost certain to affect the other one as well?" If not, just leave the functions separate no matter how similar they are.