I’m thinking of the more intentional test to see if the crash would kick up water crystals.
The Ranger 7 crash was unavoidable, considering the pictures they wanted.
More to the point IIRC, we hadn't yet developed the means for a soft landing. Also, we weren't really sure what the moon's surface consisted of.
Hadn't the Russians claimed to have already impacted the moon with no proof and the pictures taken by Ranger 7 were to prove that we actually had accomplished it?