Cleats are so important for sports. In all there forms. Blade-like or plastic or rubber or even metal.
I couldn't agree more.  We are a little league and football family, so I am well-aware of the benefits.   I will admit to feeling the rubber ones are safer. 
I can understand your need for safety, and a lot of the decision has to do with with the play environment. 
Yes...dirt and grass do.present different needs.  When mushers and dog-sledder use those attachments to their boots, are those considered cleats?
They can be since in English it is any shoe featuring those rotrusions