Currently test case run steps don't allow you to add assertions on the returns from those test steps, resulting in having to create separate extremely clunky 'Assertion' steps to assert that the data...
What I do, is pass in the salient information to the test case that I'm running, and in the called test case I include the logic to dynamically assert pass/failures based on the data that I passed into it (e.g. pass some data from a request or response from the parent test case into the called test case).
Is this something that you could be helpful to you? I find this easier to maintain, since the assertions for the called test case live in only one spot, instead of in potentially calling test cases that might all need to be touched when changing how some of those assertions work.