By all means you can add extra work on the arms to get a boost and to bring a lagging part up, so to speak.
Overall BW will dictate a larger overall size, and yes I kinda feel I am an authority on this, since I paid my dues on arm training when I started out and was much younger.
I did the Mentzer hyper intense incline DB curls followed instantly without rest to the negative chins for set after set and for months. Laying and standing tri presses and pushdwns. forced reps and negs. My arms would ache and be rather pumped for hours. The size increase was rather minimal, compared to what I do now, which is more or less a bare minimum of maybe 3-4 sets of 6-12 reps, after my big compound work sometimes only once per week...!
If I grew from anything, it was lots of heavy rowing and back work, chins etc. Triceps after BP's or presses was always some laying extensions or pressdwns.
A well developed shoulder, all 3 heads will make an arm look quite big too. And forearm and reverse curls were more or less staples, but I never go overboard. If I reached positive failure and worked them good for 3 or so sets, that is all they needed without getting past the point of no return.
A lot of thick arm size is bone size and genetics and overall BW.
Spend some time working them, sure, but don't waste time like I did. Waste the time doing heavy rows, squats, presses and deadlifts then throw in some arm work at the end.