The analysis is more nuanced than this flat tire a budget scenario.
Consider a defense. The Rams current defense with holes. Does adding x, y, and z defensive players help the team win games, produce a better defense, both?
For me I look at the player and how that player contributes to winning games. Adding an offensive player could add more value to winning than adding a defensive player.
Think of the Tory Holt vs Champ Bailey decision. The Rams offense I think was stronger than the defense by a wide margin. Adding Holt, imo, added more to winning than Champ would have added. This is speculation but illustrates the point well.
I'm fine w adding offense or defense. Best player at the most valuable position to winning would make me happy.