There is nothing wrong with having lots of static methods.
Static methods are (or should be, read on) stateless, which makes them the easiest methods to test - there's no setup, just call them.
You don't need mocking, because there is no state to deal with.
Regarding being stateless, technically static methods can be stateful if they use static variables to store state. If this is the case, from a good-design perspective they should be converted to instance methods using instance variables to store state, employing the singleton pattern if required.
