Grassrunner, everyone understands this. I don't know who you think you're teaching.
What I don't understand is why you're so insulting to Canova's method. First, you're taking a formula that he didn't even write. Someone else wrote it to assist people in doing the calculations for Canova's training. Then you come up with some extreme numbers that break the formula even though you'd never encounter those numbers in Canova's training. You're the one introducing the nonsense!
That formula aside, you're taking Canova's shorthand and interpreting it in terms of various phrases which it never meant. So again, you are the one introducing the nonsense.
Now, it's understandable that you keep thinking of things in terms of speed because Canova himself writes "pace" and because that calculator is a pace calculator, etc. But you'd put your mind at ease if you'd just think of Canova's percentages as based on time rather than pace. So while 5:30min/mi isn't technically 10% slower than 5:00min/mi because they're speeds, running a mile in 5:30 did take the runner 10% longer than running it in 5:00. But in casual speech do we say they took 30 seconds longer or that they were 30 seconds slower? So you can see how "time" and "pace" and the words we use around them begin to blend.
Before everyone had GPS watches and it became so common think in terms of pace, it wasn't so weird to think of everything in terms of time. You had a certain course you'd run your tempos on or your long runs and you'd get splits at certain landmarks with your stopwatch. You might not know the exact distances. And you might see little point in converting the times into paces even if you did know the exact distances. It's just as well to use the times.
Same for the track. It is funny to see someone who was never on a track team and has only ever run with a GPS watch get to a track for the first time.When they do intervals on the roads, they'll program their watch to automatically take a split 1200m and when the rep is over, they'll think "I did this rep at 4:50 pace" without taking any notice at all of what time they ran for the 1200. They've got no sense of what any of their splits mean and they have to keep thinking of them in terms of min/mi. It's like someone moving to/from a centigrade/fahrenheit country and constantly converting things back to the numbers they're familiar with rather than just learning what's "room temp" or "hot" or "cold" in the new system.
Anyway, the advantage of Canova's use of percentages on time rather than pace is that it makes it easier to apply the adjustments for any distance ... As well as for pace, since pace is just a matter of time on two particular distances - the mile or the kilometer! That is, as long as one can get over the awful awful transgression of doing percentages based on time and then talking about them in terms of speed! What would our Physics teacher think of us...
So again, think about people training by using stopwatches around known distances (whether on the track or a particular loop on the roads or trail), and how silly it'd be to work in terms of pace rather than time. You have to refer to pace once to get your baseline numbers from your race time or goal race time, like if your MP (or goal MP) is 3:00/km then 800m reps at 100% MP are done at 2:24. Some loop you've measured at 9.6km would be 28:48, etc etc. Then you can easily calculate what times you're aiming for in your workout for each distance at various percentages without having to put things back in terms of pace. You just apply the percentage to the time, no matter the distance.