The fibers of most shu puerhs are much broken so the infusion rate is much higher. Therefore, the number of repeated infusion is less. More compact puerh cakes takes longer because of compactness. In the case of sheng puerhs, the case is not the same. The fibers are less broken so slower infusion.
It seems to some people that sheng puerhs and tea cakes or tuocha can infuse more times because each time they are getting not so much what is inside the tealeaves.
