I think we grow all over if we grow at all. Especially for those who don;t already have massive physiques...
I grow best doing dynamic work - fast pulls seem to blow my back and traps up compared to lat pull downs or machine rows even did/could. Same w/ leg work...while back squats ar a staple for me, for size I have found Plyos and static jumps w/ DB's to give more size, sprints as well.
I wonder why this is not the case for arms...