Hello Denis
This is a good point you bring up. The token is simply a component of the mechanism used to calculate and implement shaping and policing. There is a difference however between the token bucket mechanisms used for policing and shaping. One of the differences is that for shaping, a the value of a single token is in bits, while that for policing is in bytes. You can find out more about the differences in these mechanisms at the following Cisco documentation:
I hope this has been helpful!
Laz