As JimL correctly stated, you are mixing oranges (PC1) and apples (PC2). The OEI climb performance Certification requirements are different. As 212man explained, PC2 has no first segment OEI climb requirement, so you may be able to achieve the PC2 second segment requirement at a WAT condition for which you would not be able to achieve the PC1 first segment requirement. The PC1 chart is essentially constructed by superimposing the first segment chart on top of the second segment chart and plotting the most restrictive in terms of allowable gross weight for all combinations of altitude and temperature.
I believe that you must declare whether you are operating in PC1 or PC2. If you declare that you are operating in PC1, even if you have an infinite length runway, you must use the PC1 chart.