D.
This is normal as far as I can tell but you do have to deal with it. I would just tell the babies "be gentle" and softly stroke their arm. Also try to anticipate when they may do this and hold on to their hand or arm gently so that they couldn't hit. Come up with some phrases to use with him like "we may not hit." If he is frustrated or angry try to verbalize what he may be feeling and acknowledge it. "I see that you are angry/sad/frustrated/upset."
Perhaps also, if you have to put him down just stay close by and tell him "when you are ready." and then ask him occasionally "Are you ready to calm down?" The calmer you are the faster he should calm down. Let him know that his temper tantrum is about him not about you. Sometimes they have to melt down a bit in order to regain control. Best wishes.