Thank you for contacting us! Many of the concepts taught in Saxon Algebra 1 are built on in Saxon Algebra 2. Often, Saxon will review what the student already knows (Algebra 1) before introducing the new concept. Also, Shormann Algebra 1 has 1/2 credit of Geometry and Saxon only teaches about 1/3.
The Shormann Algebra 1 Scope & Sequence shows which concepts are taught in Saxon Algebra 1.
Here is a full comparison chart: Saxon vs Shormann Math
Please let me know if you have any other questions or if there is anything else I can do to help you.