I seem to have lost the original message I was going to reply to, so here
goes, from memory.

Having a crossover between these two stories implies that the exact same
events (the series) had seriously different explanations.

I _don't_ mean just that the same events happened but with different causes;
i.e., Akane hit Ranma in both, but in one because she's immature and in the
other because she's sick.  That's part of it, but not all of it.

The series uses a sort of "Takahashi physics".  Bandannas exist in infinite
quantity, people can jump 40 feet, and explosives make big craters but only
stun human beings and cover them with soot.

But along with the Takahashi physics comes another, less recognized, anomaly
which I'll call "Takahashi psychology" for lack of a better term.  Ryouga's
sense of direction keeps him away from home for years, but he doesn't starve,
he has clean clothes, and you never see him go through the mental trauma that's
likely for someone separated from his parents for so long that it's plausible
he has a teenage sister he never met.  Ukyou dressed as a man and thought of
revenge for ten years, but manages to be a lot more well adjusted than actually
doing that in real life would imply.

And Akane hits Ranma, but it has none of the consequences that domestic
violence has in the real world.

My take on Bitter End (which may or may not be the same as Zen's) is that
it applies to Akane the same standards that are used when people say "Ukyou's
obviously nuts--she's been after Ranma for ten years and she suddenly falls in
love with him when he calls her cute!"  Bitter End says that by those
standards--by ignoring Takahashi psychology--Akane comes off as bad as if not
worse than anyone else.

TIL embraces Takahashi psychology; BE rejects it (for Akane).  Using Takahashi
psychology, Akane's actions can be explained as immaturity and not mental
illness; using realistic psychology, they can't.  That's why the two stories
don't fit together.