As someone who has a character with 6 arms..i don't draw but i've heard that if you draw the body in a way that allows for the arms to kinda..play a "shadow effect" on one another, it's as if each arm is it's own shadow of another!

I got an idea how about think of it as spider body like muffets
as seen here https://undertale.fandom.com/wiki/Muffet
put the extra arms on the back while keeping the first set on the shoulders

even thought i cant draw worth of crap i can see this as being a good idea for this or help for that matter

my character i'm trying to give more attention to is a spider XD

well shit this works even more then damn i guess i used the right example then for this but better question does my idea help you with your problem

kinda helps

thats good

I'd say it really depends what type of shoulder configuration you're going with and how many arms will be involved

you can cluster the shoulders around the human arm socket area or have each one going down the body an equal distance from the others

no matter what you go for, draw the chest out without any breasts, figure out where the arm sockets are going to be and then plan out where you want the arms positioned, I think that's the most important step to getting multi-arms right :>

and then once you know where your arms are going you can imagine where everything else goes based on them~

I hope that helps!