What are the advantages of using the strategy pattern over a factory?

Question

I have two choices to create the "ExpectedHeader", through a factory or via the strategy pattern. Maybe I should add, that a strategy-object already exists (used to customize the ExpectedModel to the TestParameters). I only would have to extend by the method #createExpectedHeader. Is there any obvious advantage of one over the other?

1. Through a factory:

public class ModelBuilder {

    //uses factory
    ExpectedHeaderFactory factory;

    public ExpectedModel deriveExpectedModel(TestParameters testParams) {
        ExpectedHeader expectedHeader = factory.createExpectedHeader(testParams);
        return ExpectedModel.builder()
                    .setExpectedHeader(expectedHeader)
                    .build();
    }

}

2. through a strategy pattern:

public class ModelBuilder {

    //uses injected strategy
    IStrategy strategy;

    public ExpectedModel deriveExpectedModel(TestParameters testParams) {
        ExpectedHeader expectedHeader = strategy.createExpectedHeader();
        return ExpectedModel.builder()
                    .setExpectedHeader(expectedHeader)
                    .build();
    }

}

The strategy interface (the first two methods are already used in other methods of the ModelBuilder)

public Interface IStrategy {

     public modifyText();
     public isRelevant();
     public createExpectedHeader();
}