Do people like this idea? Or is this too much micro-managing?
"A good idea" and "micro-managing" are not necessarily always exclusive ;-)
Closing as duplicates is the standard procedure, merging is rare, but I think that's mostly due to trepidation by mods, so if you are willing to do so are there any down sides to merging?
The only one I can think of is a loss of question content, and that can be mitigated by carefully crafting (or editing) the target question.
In meta, my question Have there been analyses to see if views of well-received answers are reduced by closure as duplicate which try to control for other factors? is well-received but currently unanswered.
...my concern has been that fewer future eyes will reach that good answer due to the closed status.
My hunch is that just closing n-1 questions does reduce visibility of otherwise good answers to them, and a well-done merger can have substantial long-term benefit by boosting visibility of all the good answers.