Don’t forget that often there is an implied subject.
E.g., the members of the committee are here. The committee are anxious to start. [Members, a regular plural noun, is the main idea. And so when ‘committee’ takes its place in the second sentence, it, too, is plural.]
The will of the committee is not to be underestimated. The committee is not afraid to weild its power. [Since committee stands in for the singular ‘will,’ it, too, is singular.]
This gets back to the above mentioned idea of whether you’re referring to the collective as a collective unit (singular), or as a collection of members (plural).
E.g., The Steelers players are hyped up. The Steelers are here to win!
The Steelers footbal team is a force to be reckoned with. The Steelers is one of the best franchises in the country.
People may choose the singular or the plural depending whether, in their mind, there is a more dominant singular or plural idea to which the collective noun is attached.
Another way to look at it is to ask “all of them” or “each of them”?
The flock is charging. The flock are going to eat you.
In the first sentence, I’m thinking all of them at once. In the second sentence I’m thinking each of them and as many of them in turn, as individuals.
Peace.
The Hivemind are telling me to stop now.