Transplanting with Coco + Perlite - ASAP HELP

I am about to transplant into 3 gallon buckets with a coco + perlite mix. Can someone please tell me the best ratio for the transplant of perlite and coco, and in what layers. Ive seen some talk about a 3" layer of perlite only on the bottom, with the drainage whole about 2" from the bottom (This idea taken from the Hempy Method). Is this a good design, and does this design mean to only have drainage wholes 2" from the bottom, and no drainage on the bottom of the bucket, or both drainage on the bottom and 2" from the bottom. My guess is to only have drainage wholes on the sides 2" from the bottom, maybe one on each side. Then for the remaining layers, what should my ratio be. Also half of my plants that I will be transplanting are in coco already in 16oz cups. The other half are in rockwool only in half gallon pots. Does this change the dynamics for transplanting the plants that are currently in rockwool, which will also go in 3 gallon buckets of coco and perlite, and will the feeding during flowering be dynamic as well, or can I caretake all the plants in the same manner. Need some some help ASAP because I would like to transplant in a couple days. THanks.

60% coco and 40% perlite.I like perlite alot so sometimes i do a 50/50 mix.Works out fine for me.