|-x--1--1--x--1---
|-0--0--0--x--0---
|-2--2--2--2--2---
|-3--3--3--3--x---
|-x--x--x--3--3---
and I could keep going...
These are all examples of a C Major chord. Which one is right? Doesn't matter. They all contain the notes C, E, G which are what C Major is composed of. The choice of voicing, including note doubling, register, and inversion, is up to the guitarist. So, your A5s are both right. Do whatever sounds best in each particular song. Sometimes playing the octave might be too much; sometimes it might be what the song needs...
"You must stab him in the heart with the Bone Saber of Zumacalis... well, you could stab him in the head or the lungs, too... and the saber, it probably doesn't have to be bone, just anything sharp lying around the house... you could poke him with a pillow and kill him."
- Aqua Teen Hunger Force, The Universal Re-Monster
- Aqua Teen Hunger Force, The Universal Re-Monster