MIRV type one C or D booster to 3 A3-4T sustainers

This has already been done on an Estes kit and i have seen something like this from der MicroMeister. If i want to gap stage one C engine to 3 A4-3Ts, do i put a duct adapter that splits the charge from the C to 3 BT5s to each A4 mini, or can i just set all 3 A4 minis in front of the C? Note i am trying an extremely asymmetric fin design on the sustainers so they will be fairly tightly "clustered" The fin design is a diamond wrap of four fins attached on each end, with inside and outside angles of 120 degrees and right and left lateral angles of 60 degrees. Body tube is attached at inside of one of the 120 degree angles. Think JonRocket Corkscrew with a diamond instead of a ring.

Sorry, ipad sent this through before i could fecally consolidate it.