Is it normal for a team to be writing in multiple programming languages?

A team where someone's writing in R because they know that language, someone writing in python, someone writing SAS? Sounds a bit messy to me but I've only used R and not worked like that.

I understand that R might have a package you can't get in python etc so you'd have to use that language, but this seems like they just write in whatever they feel like to get the job done.

datascience language languages multiple normal package programming programming languages python sas team writing