The role of the referee team sounds unnatural to me. I think the role of the referee sounds better.
I assumed it was the role of the team referee, since there isn't a team of referees as far as I know. (I don't know much about sports.)
Technically sports typically have multiple refs, so you could in a way consider them a team... But you'd never call them that in English, they're just referees
Grammatically if "trọng tài" was the main noun it would be in front of "đội" and not the other way around, so this sentence cannot be about the referee of the team, it can only be about the team of the referees.
What the heck is a referee team? A group of referees? Its very unnatural
Is "đội trọng tài" a common phrase in Vietnamese? In English, this is usually just "referees", which I believe would be "những trọng tài".
So do I bút, alas, DL rejected ít.