HFD, me old china, you being a Lashamite and I presume a gliding instructor? if so Lasham being the enormous field that it is, presents a problem. You can land that glider/tug/DC3 ANYWHERE, with all that field spread around in front and in back of you! It's too easy!
A lot of clubs we fly gliders from offer a much greater possibility of nowhere to go... think of Parham - of Talgarth, even of Aboyne, or Feshiebridge, or for that matter, the Mynd has got some pretty bumpy bits.
Your prescription for numbers, etc, has only fried my brain, I don't compute numbers at all, and I bet plenty of other student pilots would have the same difficulty. Some can navigate, some are born without that skill. Some can do your charts and your analysis, and others find it simpler to just say THAT angle looks OK, or we need to get closer in, or further out. PULeeze, don't be so rigid....o how I wish I could still fly with you and give you a hard time at shenners...
You mention in your last post that you havn't done it for real? Well, only in gliders, I have done it a fair bit. Had to change the plan when horses were observed. Or the field sloped the wrong way. Or I chose the wrong crop (maize instead of barley....) And the first time I ever landed out was trying to get from Booker to Lasham for the 50 k in a K8 glider....the farmer arrived with a shotgun...but was very helpful, not hostile. I arranged for a tug to land in that field, which was full of flints....arrgh! and got told off at Lasham for a terrible circuit. Doing it for real does a LOT for your self confidence, that's for sure.
I much prefer the BGA instructor syllabus, with the S's. Size, surface, slope. We remind the student that he can judge the wind strength and direction by his drift over the ground. But spare us the numbers and percentages, I don't think it helps those of us who have a hard time dealing with numbers. If I had to try to remember your advice, I would be hung up on the details, not the actual approach and landing.