Once you’ve passed the newbie stage and travelled down the road a bit in your BJJ career, you start to work out what you’re good at – I’m still trying to answer that question ?! Which submissions do you favour? Do you like playing from the top or bottom etc..
Now the difference between an armbar and a triangle is significant one chokes the neck the other locks the arm. The triangle to my mind is significantly more complex and requires multiple moves and hip movements – the armbar on the other hand to my mind is quite straightforward and requires tight control which is easier to achieve for beginners. The question that comes to mind is which one is easier to get ? Now we’re talking setups – both are difficult against a relatively trained opponent and its down to your prowess and own technical skills which one you get but for sure you need to have both options in your arsenal.