If two case types are actually going to perform exact same steps on two different datasets - then one best practice approach keeping reusability in mind would be to:

- Create a single case type (single work class)

- Create an abstract data class structure (for holding two types of data as concrete classes under the abstract class). Create UI rules under abstract class with a name that you would be then specialising under two child concrete classes.

- Build the case type to process data of the Abstract data class type - meaning refer pages with the abstract class name

- At runtime, at the start of the case, point the page of abstract data class with an object instantiated from relevant concrete class that you had like this case to process. 

In simple words, you would be using Polymorphism concept to create a reusable Case that processes a data instance decided at runtime.

However, depending upon number of steps and complexity of business rules in your case type this may not be best approach and may cause issues down the line in maintenance..