I'm going to disagree with this, with a disclaimer that my argument is from a rock climbing perspective.
When we build climbing anchors, we are very careful to be sure all the lines going to the anchors are equalized. The theory is they share the load equally, splitting how much load each takes, and nothing gets shock loaded if one lets go.
If you have two pedants, and your boat is exerting a 1000lb force on the whole system, each pendant will take half the load, 500lbs (not exactly of course, depending on the angle they make in respect to the mooring, but close enough). If you add two more and they are equalized, each now only takes 250lbs. If one breaks, there is no shock load on the others.
But, if these other two are slack the whole time, the original 2 are taking 500lbs each, till they break. Depending on slack, your other two are now not only going to take the full force, but will be subjected to a significant shock load.
In climbing situations, this has killed people.
Chafe of course is still a huge issue. Chafing is directly related to the amount of strain each cord is under, among other things of course, and I would argue that cutting the load in half for each pendant will significantly reduce the chafing.
That whole premise is mostly based on breaking strength. Properly sized pendants do not break and are far from breaking strength even in storms. Our primary pendants are each rated at 31,000 pounds. What does happen is they chafe. With equal length pendants they chafe nearly equally until the both fail. I have watched this and observed it many times.
My neighbor Tom had this exact thing happen to him in that storm pictured above. His pendants were equal length and both parted at near the same time. His boat drifted many miles before coming grounded near Portland..
Quite by accident I caught pictures of his boat drifting away. I could not see it from land and only saw it when I cropped in on the photo and cleaned up the rain clutter.
This is how close his boat is to ours:
The boat in the distance with her stern to us is his boat drifting away after parting both of the equal length pendants:
These are the bow chock end of his dual equal length pendants and they were less than a month old:
Our boat survived that storm beautifully only 80' away on triple unequal length pendants.....
Another boat neighbor, in the same storm, lost one pendant, his primary. His secondary, longer one, was still in near perfect condition when the storm ended.
Boats also yaw back and forth in storms and rarely equally load both pendants at the same time. If on every yaw port wears then stbd wears then port wears then stbd wears etc. they do fail within a short time of each other even though it may have taken 6 hours for that to happen. With unequal length pendants you buy yourself almost double the time because you now have a bran new pendant.. Seen equal length pendants fail too many times to do it any other way on my own boat. I will NEVER go back to dual equal length pendants.
This is an email I got from a guy who read my article:
I wanted to write you to say thanks. We lost our boat 6 years ago in a dreadful Noreaster. I had gone beyond the towns requirements for years by using two bow pennants. After every storm, we are highly exposed, I always found them equally worn away but kept using that method as I felt it to be better. When we lost our boat both pendants had worn through at the bow chock location.
After reading your article I chose to try the two different lengths for my pennants. We just had a storm that was worse than the one we lost our last boat in, you did too, and all I can say is thank you. The shorter pennant broke in the storm and the second one saved our boat. Seven boats around us broke away and went up on the shore. That second pennant hardly showed chafe and got us through the tail part of the storm with reserve left. I think I will order a set of those yellow pennants you showed for next year. If I ever run into you in Maine I will buy you a beer.