Start CP grinding now of chapter 11?

I need to know if I should start CP hoarding now, in the Fifth Ark, of wait for Gran Pulse. I am in chapter 10, 3 of 5 basic weapons maxed. Hope has Ninurta in my save; he didn't start with it. Hence the 5. Also, is it a good idea to base your party on HP right now? I'm planning to have a 1-Medic minimum party config. The battles take longer but I fare much better this way.