I find that part quite puzzling as my Smoke and Mirrors do not warp or clump right out of the box unlike my Guardians and Centurions.If it is the way the cards are made and stored , you should make some changes and tweaks.
I suggest that you try using Guardians and Centurions using the Aristocrat Finish and Stock.
Cards sometimes bend and cards sometimes warp because they're made of paper and that's what paper does. In this case, the problem is not the stock or finish - it's that something happened with those two decks sometime after they were finished that caused them to warp. It could have been a store employee (not under the control of theory11) that left them in a hot car. It could have been a delivery from theory11 to that store that traveled in a hot Fedex truck on a rainy day. It could have been a delivery package that was left outside for a few moments on a humid afternoon. There are tons of possibilities.
That said, this is far from conclusive evidence of an issue with the cards themselves. Out of tens of thousands of Guardians and Centurions sold in the past year, we have heard no reports of widespread issues. As mentioned previously, we use only the best card stock, finish, and presses at USPCC. Our quality control is unparalleled, but our control only goes so far. On rare occasion, things can happen to cause a deck to get ruined from time to time. For those decks that are purchased directly from theory11, we stand behind them 100%. For decks sold outside of theory11, we do our very best to make sure they get as much TLC as we can. But on rare occasion, things like this, unfortunately, can occur.