I dont know why would you want to play with your starters when you are leading by 20-30, unless you need them to have 48 mins for GS(you certainly dont want some of your star players to get injured in last minutes of a game that you are leading by 20 points)... It is maybe because I had never lost a game in which I was leading with big margin, but in my opinion if your reserves can lose 20-30 points you should rather consider buying better reserves, than supporting this suggestion...
In NBA today, you have a lot of centers that are really bad in jumping, just like Kendrick. Those are all big and very strong guys, and because of their strength they can make a good position near the basket, and compensate for their lack of athleticism in jumping... Here are just some names popping my mind on this matter: Nikola Pekovic, Marc Gasol, Zach Randolph...