I have a few rules for you which I made up just for your case. Follow them rigorously:
Rule #1: There are no taboos in writing!
Rule #2: There are no taboos in writing!
Rule #3: There are definitely no taboos in writing!
Now I hope we have made that point clear.
Yes, there are rules in writing, what you should do and what you shouldn't. But for each rule there is an exception where you should do exactly the opposite of what the rule tells you. The prerequisite for using or breaking rules is understanding the rules. You are in the right place ;)
Ok, back to your question: You want to avoid confusing your readers when introducing all these characters. First: You cannot please them all. There are readers who get confused with too many characters, no matter where you introduce them. A pity, but that's how it is.
So let me tell you a story about Margret. She had a sister, Susann, and they both visit her mother Ann. They met Marie on their way to their Mom's house, the daughter of their neighbor Kate. Kate and Laura, the aunt of Ann, know each other since childhood. Sadly Laura is sitting in her rocking chair all day and Kate doesn't have much time visiting. But she always loved that marmalade Marie was cooking.
Now ... where was I ... oh, yes, who is my main character?
Yes, I'm overexaggerating, but I wanted to show you, that introducing characters in a short time period (all in the beginning) can be also very confusing. Take your time introducing the protagonists to your audience. But that does not mean that you should bore them. Writing is so lovely complicated, isn't it? :)