I read this series before discovering Omega Force. I enjoyed it so much that after going through all 3 of the books in this series, I then burned through all 13 books of Omega Force and looking forward to more from each.
However, I went back and reread these 3 while reading Omega Force. Here is how I would recommend reading this series. Go read Omega Force Book 1-10, Then Read TSF B1 (Marine) and alternate back and forth with OF B11, TSF B2, OF B12, TSF B3, and then finish the rest of OF.
I hope this timeline helps!!