Combining simulation projects by copy paste or aggegator project?

I created multiple simulation projects.  After that, I combined them into one project by copy and pasting slides...

For example, I created a one simulation project like:  "How to Open a document in MS word".  The second simulation project is "How to print a document".

I combined the 2 simulation projects by using copy paste of slides method to make it as 1 whole project called "MS Word Elearning" project. And in this project, there is a menu slide as first slide with customized buttons  so that it will allow user to jump into the specific task or which i now call it as topic.   For example is, Jumping from the menu slide to the first slide of "How to print a document"

The question is:  is this the correct method? or should i use Aggegator project? I actually dont understand clearly the objective of Aggregator project.