I have always settled on six bottom, six and four deck. Sometimes six, six, six. The four only goes to the rail apex so not much strength there. But double six is fairly strong.
That which can be assorted without evidence was read in an illegal magazine.
May I venture to say that you need to match your bottom lam to the rail lam with at least 8 oz. do a double 4Oz bottom with full laps onto double 4oz deck with a 4 oz patch to make it 12 for the feet on standard eps.
I have built boards with 18 on rails, 6 on bottom, rails stayed intact upon impact, then where the 6 met the 18 it failed.
the main thing is to surf empty breaks wit lots of tubes and prevent rail damages that way
Yes when you impact strong rails, bottom lam delam on the flat near rail. Good reason for staggered laps from deck lam on bottom and/or add reinforcement bend on flat around rail when lam bottom.
"the main thing is to surf empty breaks" since covid it became crazy where I live, south French coast, so much guys come and stop here for surfing. All breaks are saturated even before and after sun lighten waves... Became impossible to surf without danger, all mates asked me bigger boards to be able to take waves and stronger one to resist other boards impacts. Many guys start successful ding doctor business and surf schools. A nightmare. Some "older guys", like me, move to other sports.
I do double layers on the bottom and up to 3 on the deck with my stringerless EPS boards. My latest has double 6 on the bottom and double 6 on the deck with a 1/8" Balsa skin. I also do the lams with a single layer of glass, so I do 4 lams. Bottom, then deck, then add Balsa then another layer of glass, then a layer of glass on the bottom over the boxes. Overkill and heavy, but very strong, and should last many years. I've done double 8 oz cloth before. If I had 4 oz cloth I'd mix it up, but right now I just have a roll of 6 oz. Without the second bottom lam, the board is not heavy, but I feel better knowing the boxes have glass over them. I've left the second bottom lam textured (no fill coat) on several boards. Those were an experiment to see if having the textured bottom helps or not. One of my favorite boards is like that.
So a 6&6 gives me 12oz. At the rail. A little more on the deck with the layer of4oz. Cut at the deck. If I remember right Loehr's DVD Glassing 101 was all 4oz multiple layers. What we sometimes fail to consider is the size of the strands in the weave.