As the former Director of Curriculum for one of the largest educational companies in the world, and as a former Director of Instruction for a school program, perhaps I can provide some insight into the theory of course design and instruction. The most popular resource for course design right now is Understanding by Design, by Wiggins and McTigue. My comments are consistent with the theory presented in that work.I will point out that I took a fundamentals course with a guy who had full cave from another agency (and his buddy) and not one of us even got a rec pass in doubles. (We all got provisionals, which means the instructor thinks that it is possible for you to get to a passing skill level in the next 6 months.) I was by far the least skilled, but it was like my tenth dive in doubles.
It's a "somewhat more demanding standard" to enter the GUE tech programs than a lot of other programs have for their tech graduates.
In designing a course, you work backwards with the goal of creating success for the student. You start by identifying the required content of the course, the standards for that content students must achieve, and the means by which that achievement will be measured. You then design a course sequence and parameters that will enable students to achieve those desired outcomes. You start by identifying the prerequisite skills a student must have in order to begin the course (you don't put a new Algebra I student into Calculus), and you plot a logical instructional path that will take a student from that starting point to the identified ending point. Continuing with the math example, one skill should lead logically to another until the student is done with the course, assuming a realistic time frame--students are not going to get through Calculus I in a week. The content of the course, the standards, the assessment, and the instructional strategies should be aligned to work together to achieve a successful outcome.
In theory, then, a student with the required prerequisite skills and good work habits will pass the class, assuming effective instruction of a well designed curriculum. If a course with such students has a high failure rate, you have to look for problems in the course design or the quality of the instruction for an explanation.