The thing about how merges are presented seems orthogonal to how to represent history. I also hate the default in git, but that is why I just use p4merge as a merge tool and get a proper 4-pane merge tool (left, right, common base, merged result) which shows everything needed to figure out why there is a conflict and how to resolve it. I don't understand why you need to switch out the VCS to fix that issue.

Even if you don’t use p4merge, you can set Git’s merge.conflictStyle config to "diff3" or "zdiff3" (https://git-scm.com/docs/git-config#Documentation/git-config...). If you do that, Git’s conflict markers show the base version as well:

<<<<<<< left
||||||| base
def calculate(x):
a = x * 2
b = a + 1
return b
=======
def calculate(x):
a = x * 2
logger.debug(f"a={a}")
b = a + 1
return b
>>>>>>> right

With this configuration, a developer reading the raw conflict markers could infer the same information provided by Manyana’s conflict markers: that the right side added the logging line.

I'm on my phone right now so I'm not going to dig too hard for this, but you can also configure a "merge tool" (or something like that) so you can use Meld or Kompare to make the process easier. This has helped me in a pinch to work out some confusing merge conflicts.