wow, that's a job for MicroMeister, aka Mr. cluster. Now how bout this, a I200 in the center and 8XD21..... What's the proper way to pronounce "Shread".....?
ScrapDaddy: Tell me, how long is the body tube of a Big Daddy? And how long is an I200? How much nose weight would you need? How large of a parachute would you need? And once you accommodate the I200 and the nose weight, where would you put it? Finally, what would be your plan for igniting all 9 composite motors on the pad? What are the materials that the Big Daddy is made of? What would be the maximum acceleration and maximum velocity it would undergo on that motor combination? Unless you can answer these questions,
how do you know that the Big Daddy would shred during boost? What
simple things could you do to make it stronger if you did find, based on your analysis, that it was at risk of being torn apart by the launch stresses?
Also, what would putting 8 D21s in it do for it? Would it make any appreciable difference over launching it on just the I alone? You are adding a great deal of complexity, not to mention expense, for what purpose again? (And do tell us, please, how much this would cost in motors for one flight.)
People in this hobby don't just slap together high power rockets and then chuck any old motors into them and wait to see how they launch in order to find out if they will even fly. Can a rocketeer that has no experience with launching rockets on clusters, let alone high power rockets, make a casual observation like that without doing an iota of analysis?
MK