Private school? Didn't think kids could write so well these days.
I would advise that; to help minimize risk, you can linebreed on particular dogs that have been successfuly linebred upon before. In west-workingline breeding, lots of linebreeding on Fero, Troll and Yoschy has already been conducted, and not at a lot of terrible expense. Same with the Ingo, Held and Bero bloodlines of the czech dogs.
Those are the two that I have concentrated my linebreeding interest in, but the point is, neither are completely uncharted territory. I will not be the first, and were I to push the evelope, it would be in more recent generations of the same lines (i.e., a "2-3" on Bero's grandson, Faro Policia), or in combination with different linebreeding of weaker strength (further back, but of an unrelated line, like a 4-4 Cordon An Sat). Both Faro and Cordon have established themselves successfully in previous linebreeding already. Some of the "guesswork" will have been eliminated by those who have gone before and helped pave the way.
Selection of the animal's phenotype is and always will have the greater impact than looking at pedigree alone. Even same-siblings linebred 4,3-4,4 on so-and-so have the potential to be very different from each other in outward appearance and general behavior.