Well, do you have anything else that establishes the character being a "fish out of water"? And how much space does the scene take up?
A short anecdote might be innocuous, and aid with characterisation, I think.
Conversely, a long section that does nothing more than provide that note of characterisation might perhaps be cut, or reduced. Or alternatively, it might perhaps have other elements woven into it, such that it serves more than just that one purpose.
All that said, I'm not sure that I agree with your prior commenter on the original second scene. I don't speak from a position of authority here, but intuitively I don't think that it's all that great a coincidence to run into someone twice, even within a large city. Doubly so if the two happen to operate primarily in much the same general region of the city.
Edited by ArsThaumaturgis on Apr 20th 2020 at 5:56:55 PM
My Games & Writing
The simplest solution is to make it so that it isn't a coincidence anymore, but that might require more character development than you want to go into. If the two characters have similar needs, interests, problems, hang with the same people, live in the same neighborhood, or have anything else in common that might impact the plot, then that can become the basis for bringing them together, and if you write it well, it won't seem too unlikely to the reader. But this means that you will have to develop each character with enough detail to determine what commonalities would best serve the story. For example, if they share a similar fighting style, the protag could run into someone who says "Hey, I just saw someone who fights just like you." When the protag goes to see this person out of curiosity, it turns out to be the secondary character. Something like that.
So in my story, the protagonist moves to a city and has trouble adjusting. Early on, there's a scene where they inadvertently insult someone. In my original draft, my protagonist was supposed to run into them again and the two would get into a fight. However, someone pointed out that it would be a huge coincidence for these two people to randomly run into each other in a big city. I ended up changing the scene so that the protagonist gets into a fight with a random mugger. The thing is, without the two getting into a fight later, I'm wondering if the original scene is pointless. The only thing the scene serves is to show that my protagonist is a Fish out of Water. Should I cut it?