Hmm don't know. With all due respect to PG and crew, VCs and angels seem to do their homework as well. Actually their initial filters are probably much more restrictive so I guess it would depend on how you calculate the batting avgs.
I suspect for most investors passing on someone who goes on to be wildly successful hurts a lot more than investing in multiple failed ventures. Given that, having a longer more thorough process may not be beneficial. At best a long process can reduce the number of failures by refusing to invest in them but it will never increase the number of successes which is limited by the number of people who ask you funding.
I'm kind of surprised that no well funded VC funds have come up with the idea of just handing out 5-10k to every single not obviously doomed startup they come across in exchange for a few percent of each company. They could call it shotgun investing.
That just simply isn't true. Early stage is much quicker. The only time a VC needs 'months' to do dd is when there is a substantial company already, so when you're doing a late-stage investment, usually in the millions.