Yes and no.
Originally I just wanted them be styled simply after the Sandman baseball, and the Wrap Assassin ornament. So there's an unused Smissmas ornament style that never got made.
Because the original pitch was "what if Scout had a grenade belt similar to the other offense classes, but with his baseballs?" And I think Lazer leaned more towards the "grenade" aspect of it.
The connection to Fallout's baseball grenades was an after-thought. They were not directly inspired by them upon inception.