That type of yard stick is already in use, just that the current required numbers are lower. If someone is going to cheat, they are going to cheat. An instructor can use judgment if he thinks the logbook is legit. Now if the instructor is in on the cheat, there's no independent verification the skills were even performed much less the required dives.
Yep, that is just the problem, I have encountered too many operations where the $$ is more important so it's more often a question of:
Instructor: "How many dives have you done?"
Student: "100"
Instructor: "Can I see your log book?"
Student: "I'm sorry, I lost it." or "I filled up my first log book so I started another one with the first page following on where I left off in the one that ran full. Oh, and I don't have the full one here with me either."
Instructor: "OK, no problem."
IMHO the log book thing as a measure of experience remains a flawed practice because nobody can or really wants to enforce the minimum dives yard stick rules unless they are ok with losing the $$ and having the student bugger off to some other instructor who couldn't care less and would take their greens with a smile on their faces just the same. The end result is that whether a log book is produced or not, whether it's valid or not, the diver is inevitably allowed to start the training. Now I'm sure there are instructors/LDS' who would rather lose the $$ but honor the rules in an attempt to at least keep within the intended spirit of the yard stick rules, but I do think they are by far in the minority.
Now, if a diver is required to enter a DM or AI/I course as an intern who is required to perform said number of dives while being on training where the dives can be verified, then I'm willing to bet the yard stick becomes much, much more accurate. But people won't want to do that because that means working harder and longer for their "babe-magnet badges" :mooner: instead of going from OW->OWSI in three months for the right price. It all boils down to economics and maximizing profits.
The bottom line is - trusting a bunch of log book pages that claim to indicate a diver's level experience is IMHO mostly wishful thinking.