He got info that his wifes killer was on the train is a very quick scene he gets handed a note. The Wolf, who recognizes Ladybug from his wedding, where his wife was killed. The Wolf mistakenly believes Ladybug to be one of her killers instead of The Hornet

He didn't. He was getting on the train to kill the hornet, and completely coincidentally run into Brad Pitt and recognized him from the wedding, and assumed that he must have also been part of the poisoning plot.

It's just another example of Brad Pitts character having incredible bad luck throughout the movie

He did not.

He knew the Hornet was on the train. Ladybug was a coincidence.

It goes like this:Cartel kid's dad dies, and he inherits his necklace and knife. His mom dies of cancer, and he hits the road on his own as an orphan.

He becomes such a famous streetfighter that the Cartel recruits him.He uses his golden Cartel gun to save everybody's life during a drug deal gone sideways. This makes him a favorite of the Cartel boss, and catches the eye of his future wife. They start giving him envelopes, and he acquires a lot of his signature black/gold clothing items from the bodies of his victims. His wall becomes crowded with people who have been killed by him, so because he is putting violence into the world he gets violence back.

The White Death targets El Saguaro while consolidating criminal power globally, and he hires the Hornet to do the job. She is a homicidal maniac, so she elects to kill EVERYBODY at the wedding by poisoning the cake. Ladybug was on a nonviolent job at the wedding, probably to steal something, whether valuables or information. Not made clear. Ladybug is chronically unlucky, and bumps into the Wolf at his own wedding, spilling red wine on his white wedding jacket. While the Wolf is trying to blot wine out of his jacket, everybody takes a bite out of the poisoned cake and dies.

The Wolf is now a wealthy widower with no boss, no wife, no friends. Just a violent man full of grief whose schedule just opened way up. So he demands the identity of El Saguaro's assassin, and gets the details on the Hornet. So the Wolf finds out she'll be on the train, and he shows up wearing his father's necklace, carrying his father's knife, wearing the glasses he took from a gang leader he beat to death in the street publicly, and wearing his wedding suit, still stained with wine. His blood is boiling and he's ready to take his revenge.

Then what happens? The train doors open, and he sees the wine server that bumped into him at the wedding. He doesn't know Ladybug had anything to do with killing his wife, and in fact he didn't. But the coincidence is so ridiculous that he makes the reasonable assumption that Ladybug was somehow involved and helping the Hornet. Just SHOWING UP on that train on the other side of the planet is too much of a coincidence for the Wolf to believe, so just like that he gets included in the vendetta.

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Just rewatched most of it and I still don't know about that.

He read the script.

But like no rando people or other assassins are concerned about all the details he exposites no person?

I even think smokin Aces is a better movie. They just turned the building into a train.

How is Brad Pitt a world class assassin when he is constantly discussing what he's doing outloud?