Julia to your original question: the programs are best thought of as a container to enable fast cloning and better reporting. They combine the smart campaigns you're using with the relevant assets, so for example you can create part 1 of the program for Grade 1, then clone it to create part 1 for Grade 2.
Programs can feel like too much effort, but they can help long term with reporting, as you can measure the success of each program and see which emails (via their program) perform the best.
Engagement programs are a step up, in that they simplify the smart campaign itself and add some more reporting capabilities around content engagement metrics.