I am afraid, your idea will NOT solve your original problem.
I suspect that your original problem was the one discussed at the following topic. Am I right?
You thought that you can workaround the “Method code too large” problem by splitting a single large Test Cases into smaller pieces and re-assembling them by callTestCase().
But in fact, no, you can’t. The “Method code too large” error occurs when the run() method of the Main class derived from 4_RunAll will become larger than the JVM limitation (64K bytes) in size of the compiled JVM byte code. AFAIK, the run() becomes as large as the sum of component sources (1_CreateUser + 2_UpdateUser + 3_DeleteUser).
Q. How can you definitely workaround the “Method code too large” problem?
A1. You can make a Test Suite which combines the 3 Test Cases. If it is favourable for you and you can avoid using callTestCases(), it is the easiest.
A2. Or You want to rewrite the source codes of 1_CreateUser, 2_UpdateUser, 3_DeleteUser to be more compact. How to? — I don’t see, as it depends how your codes are written.