I think there is a misunderstanding on what a starter pack means here because it literally tries to help with this point:

search for people to follow when people are thinking in topics.

There is no way to pick a wrong starter pack because you can pick whatever you want, one pack, two packs, cero packs.

It's just a list of accounts that you can follow in bulk

edit: well looks like you won't be able to have a 'follow all' button on mastodon but its the same idea