You are misreading the cut and paste. For USCG purposed you only need one of the three groupings. The USCG believes and is set up to put an aircraft on top of any vessel in US waters. They want you to be able to mark your position for them day or night. Smoke Day, Flag Day, or USCG flares day or night. So three approved flares and you are good with the USCG. They do not say anything about flares you shoot from a gun. The correct flares in your hand is just fine with the USCG. Once you leave the water protected by the USCG any vessel and crew will be better served with equipment meeting the more robust SOLAS standards. If you want someone to see you or notice you from a distance. You want proper parachute flares that launch out of a single use handheld device. The entire sky lights up for 30 seconds or more. The life of your crew may just depend on it. There are near worthless and can get you jailed in many jurisdictions.