I find this to be very jarring, and at times outright confusing, and I was wondering what the benefits of writing like this are?

When I write, I stick to a very close 3rd person and I only follow one character per chapter. I think that this allows me to keep the narrative flowing and not confuse readers by changing POV's.

There are cases when the author may want to tell what every character is thinking at one particular event. In a lot of situations, you may want to tell the story from one character's POV, and then retell that situation from the others. But this is usually done when the characters are in different locations. Re-telling the same situation from another character who was there becomes tedious.

Of course, if violating a limited POV is too much, all you have to do is have the other character reminisce about that event at a later point.

The other benefit is uniformity. In The Three Musketeers, there is constant omniscient POV over D'Artagnon and Co., and what it shows is that all these people are on the same team. It gives the different reasons and what they're thinking, but it confirms to the reader that all of them are protagonists.

It's split into parts, which are further split into chapters. Throughout the story the Russian antagonist drives all the major events, effectively manipulating the Japanese protagonist. In the first part the story is seen from the point of view of the protagonist, and the antagonist is simply know as "the assassin".

Then, in the second part, that same Russian, now by a different name, goes back to his home in France to spend time with his girlfriend (though this also doubles as yet another alibi for him). She doesn't know that he's been to Japan; simply that he was going to Russia to visit some childhood friends. They have a lot of trust.

So the second part, as I've got it, begins with the French girl waking up and enjoying her day, and waiting, knowing he's coming back today. I also use this chapter to establish her as one of the main characters in the story, obviously.

But then at some point here in France, I'm going to need to reveal that he was behind it. Two major points here:

1. The reader will find it extremely obvious that he's the assassin, which is fine.

2. She can't know. He continues lying to her. So it has to be done from his point of view.

But when, and how, to switch? Can anyone help me here?

Edit: Of course the same sort of scenario could be done on a smaller, or larger, scale than Russia, Japan and France, but I thought I'd elaborate on the plot a little in case it matters to anyone.