I just went through Sage in SLC and they definitely did not have a student / instructor ratio of 1:1. On the road driving IS one student / one instructor per truck, though.
Sage Corporation in general is like all CDL schools in that their primary purpose is to get you your CDL rather that to fully train you for a trucking job. However, I thought the instructors at Sage in SLC were pretty awesome guys who did their best to give students the best possible training within that framework. If you are in the area I highly recommend them.