Yes, experience is in the 4-5 year range. I don't know what their previous stock compensation (at earlier companies was before they made the switch). I assume that that may have had a role to play in these numbers since it would be virtually impossible to hire someone by giving them less stock than what they already have.
That said, there's a sufficient sample of such folks that I am very willing to believe that such numbers are entirely reasonable, and not hard to get.