Feature request: a merge strategy that makes any file difference a merge conflict

Git's built-in merge strategies, such as ort, sometimes create a clean-but-incorrect merge. A merge driver or a mergetool cannot be used to correct such problems, because a merge driver or mergetool is only called when the strategy resulted in a conflict (so far as I understand). It is challenging to write a merge strategy, but it is much easier to write a merge driver or a mergetool.

If git had a strategy that always caused a merge conflict (even when the differences are mergeable), then a merge driver or mergetool would be called on every file difference. This effectively permits a user to completely replace git's merge strategy, without the difficulty of writing a merge strategy.

I realize that the proposed strategy would likely only create merge conflicts when no two of {parent1,parent2,base} are the same -- that is, only when the low-level merge driver `git merge-file` is called. That is fine with me.

What do you think of this feature request?

Thanks in advance, -Mike