Well, let's run through five of the most common reasons you'll want to play four copies of a card
If your deck meets the constraint, you may choose up to one copy of that card as your companion
See the combination of artwork quality and price below and you might be inclined to agree
If The Flood Of Mars hits the battlefield, odds are, unless there's a board wipe or it gets removed early, the entire battlefield will be turned into copies of it
That would be a pretty reasonable thing to do on most Turn 2s, but is a much bigger ask on Turn 3, which is where higher plot costs prove to be detrimental the further behind you are on the battlefield
And, no matter how much she wishes it were otherwise, Rowan cannot blame them