Ollie,
On the face of it, what you say sounds sensible. But it's not as simple as that. A friend of mine recently went through the Class 1 process, he'd hit a milestone age that required the whole shebang. His markers whilst being high were 'within tolerance' but led him to a stress ECG. And there it was, a congenital issue that required open heart surgery. Interestingly the normal ECG was fine and the stress ECG met the required standard for a Class 1 to be issued (and it was!) It was abnormal electrical activity that triggered concern and further tests.
Long story short, with your solution this fella would have gone undiagnosed. A sudden cardiac event would have happened, it was not a matter of if but when. This fella was not overweight nor did he have any glaring symptoms. There are some pilots that are quite happy to do the Class 1 medical process as it stands, it's the one time of the year they'll see the inside of a doctors office!