Please take this potential curriculum sequence with a grain of salt. You know your own students far better than I do, and you will likely need to make adjustments based on what they need. Consider this as a starting point.

The color groups represent levels of differentiation that I have used across multiple classes. Most of my classes have had students from at least two of these groups simultaneously. This also allows students to continuously improve their music theory skills even when taking the same class for multiple years.

All assignment types should be repeated until students reach mastery of the required skills. The calendar is less important than making sure each student is ready to move on, especially considering that each new assignment type incorporates the previous skill and adds to it.