It's important to note that Sam also suggested an increased equity grant on top of the 10/20/30/40 schedule. The expected value of 10/20/30/40 only matches 25/25/25/25 if the overall equity grant under 10/20/30/40 is higher to begin with. Depending on the time value of money, and upon one's personal opportunity costs year over year, that equity award might need to be significantly higher. Alternatively, as Sam suggests, there are compensating mechanisms (new grants, vesting acceleration based on performance, etc.).

All things being equal, I wouldn't take a 10/20/30/40 over a 25/25/25/25, because it would be economically irrational to do so. But all things aren't supposed to be equal under the two structures.