Why does this recipe call for so much yeast?
Having that much yeast is doing two things for this recipe:


It will give it a nicely yeasty flavor
It will shorten the rise time.


Yeast requires water to be active. This recipe, as is often the case with enriched doughs, has very little water in it. There is water in the cream and the eggs but not much and the yeast will be competing for it with the sugar.
Because of this rich doughs often take a long time to rise. 

This recipe was used by a restaurant that probably needs faster rises. The cost of the yeast is cheaper than the cost of the extra time to rise. The extra yeasty flavor is a bonus.