Hi Nick,
Yes, it’s likely that a body with higher density or cohesive strength would be far less affected. The NASA news release says:
“The recoil from this blast of debris substantially enhanced DART’s push against Dimorphos – a little like a jet of air streaming out of a balloon sends the balloon in the opposite direction. To successfully understand the effect of the recoil from the ejecta, more information on of the asteroid’s physical properties, such as the characteristics of its surface, and how strong or weak it is, is needed. These issues are still being investigated.”
We still need to wear our tin hats…
Alex.