It's the habit that Gulfstream have to include 4 initial type ratings which each new plane sold... On 2 or 3-man private operations, chief pilots and other suspicious types end up getting typed.... Or else the remaining rating is sold via a training broker, and some hopeful ex-airline types himself and goes skulking on the freelance market...
Not such a problem in the US where small aviation companies have learned to negotiate sales contracts and exchange the additional rating for some other goodie...