Partitions in dangerous game calibers like 375 and 416 are very tough bullets.
The partition portion of the bullet is farther forward as opposed to the smaller partitions. As a result, they tend to retain at least 70% of their original weight. The front core is designed to expand rapidly and loose mass creating secondary fragments and larger wound channels.
Having lost a significant portion of the front core, the front of the expanded bullet has a smaller surface area than bonded bullets.
The smaller frontal area together with the 70% weight of the rear core tend to penetrate very deeply. Generally deeper than bullets with larger frontal surface area.
It’s not hard to test this for yourself. Using dry paper( news paper or magazines), you can test partitions against other bullets. Use 36 inches of paper and test the bullets side by side.
Modern dangerous game partitions compare very favorably with A Frames in test media as well as cape buffalo and large bears.
I just had three well known PHs spend a few days at my Alabama camp. One of them told me he had recently guided John Nosler. Nosler killed 4 buffalo bulls with Nosler bullets. Nosler bullets are field tested very carefully. They work.
All three PHs said that modern bullets from Hornady, Nosler, Barnes, and Swift are excellent and none of them make bad bullets today.