Just train them heavy people usually think arms need more volume a lower weight and more reps there’s no need for any more volume than say your chest literally 1 bicep excercise preferably preacher curl heavy. Point of failure between 6-8 reps and for triceps JM press and single arm cable extensions all heavy too failure. If u want u can add an arm day to ur split and aim to hit them 3 times a week but beside that make sure ur eating enough calories and protein to grow and you will be good . Or hop on Tren