Yup, your legs are gonna hurt today. Which means being smart about how you break it up will either save some of your leg energy for that final couplet, or it will leave you dying by the time you get to the burpees. So anticipate how much you'll be hurting by the end, and don't go too hot on that intial couplet. You can think of the beginning as a way to set in the pace, and by that 12-9-6, you hopefully are able to pick it up and sprint by the end. So pace it as well as you can, expect it to burn, and embrace the fire.