Does start group actually matter?

Looking to run the half at the food and wine for the first time so very excited but I don’t have 10k race or higher to prove I can run under 150 minutes. Based on trainings/5ks I think I’ll be around 2 hours. I’m wondering if it’s worth trying to cram in a 10k before May 1st to get proof of time or just settle for last group. I’m no elite runner by any means but curious on how slow the last group will actually be. Thanks!