I said he's not a good on-man defender, for he's not strong enou

Isn't that the very reason they acquired Perkins, to bear with his ugly and miserable face?:)

Ibaka is a great shot-blocker, but that mentality makes him tend to meet the driving opponent at the rim, instead of in the lane. That opens up a lot more different options for the driver.

Let's not look far, to me, Splitter is a better on-man and on-ball defender.