Blasters optional stems from the fact that some countries have extremely protective gun laws, where even toy blasters would be illegal. We still want those living there to be able to become members. Since level 2 and 3 are optional, the requirements are higher, including a required blaster. Maybe that the wording could use some improvement, but so does the CRLs themselves.
My pro-tip is to focus more time on looking at how the centurion-costumes here are build and following that, rather than the CRL since that gives you more visual input on how to do things that might be complicated to express in text.