I have 4 dbs, are two of them redundant and a field of another?

Using Meteor I have the following db collections for a fantasy sports site I am working on.

Stars - the draftable people, fields of name/attributes/events/etc

Events - tracking the Stars actions, fields of points/date/stats/etc

Matches - used for the competition, fields of roster depth/wagers/match type/dates/competitors/etc

Rosters - where the user inputs team composition, fields of positions/match type/depth

Currently Events acts like a Schema which has the info in Events get linked into an array in Stars events field. This seems to work and I dont think I need to change anything but I am a novice.

I think the Matches & Rosters could be redundant as they both contain some of the same information. Because each Match will have multiple users I am having each user fill out their own Roster db, which then gets referenced in the Matches db. Is this something that I should be keeping separate? It seems to be creating more work for me although it seems easier to manage from my beginner perspective. How would a combined Matches and Rosters database look?

Thanks to those who can help out with some guidance.

I am writing as much of this as possible using Meteor Kitchen so there aren’t any database packages that I am using. So hopefully anyone helpful enough to provide some suggestions please don’t recommend anything that I cannot just use at the Collection/mongodb level.