Puppy becomes aggressive when given a command

I have a 9 week old australian shepherd male puppy, Duke.

This week I started noticing when I would give him commands he would frequently lunge at me, bite at the air in front of my toes/hands, he aggressively bit me a few times when we were just relaxing next to each other (I wasn't touching him or in his personal space), deep growling, etc.

The behavior started shortly after the following events:

• I brought home another rescue puppy - he was 4 weeks - and he was in our house for maybe 3hrs as I arranged housing for him. Both puppies got along splendidly but when I moved the younger puppy into Duke's crate (was trying to transport the rescue pup to his foster family), Duke was placed in his playpen and lost his mind. He started barking at the other pup and the other pup started barking back. Big barking fest for 5-7 mins.
• After the rescued puppy left, my husband's best friend and gf were visiting and they got into a major screaming match in front of Duke. It was a pretty awful fight.

I'm not sure if Duke's new behavior is a result of the above or if it's this week's training regime as I have started implementing impulse control.

Here is what Duke's current training looks like:

• calm capture throughout the day.
• an engagement protocol 1-2x day for 30sec-1min with hand feeding. sometimes will include the touch command to increase bonding.
• Duke does not go on walks - he absolutely hates it and I think it's partly because of the extreme heat. I'll do loose leash walking exercises with him in the backyard/porch or do some sort of smaller command based game to get him moving.
• socialization activity 2-3x week - thus far he has not exhibited any reactivity to anything
• lickmats, lick bowls, or pupsicles usually in the AM either in his spot or crate.
• carrot or dental toy covered in a treat like peanut butter, applesauce, or yogurt in PM for a chew. He also has chew toys inside of his crate and playpen.
• tug-o-war periodically throughout the day.
• preventative resource guarding training: making sure never to snatch something from him, try to distract him with the scatter method, or use the trade method.
• for high energy episodes during training, I'll use the scatter method, throw his reward away from me for him to go find, or have him chase me for his reward.
• he sleeps on and off throughout the day: potty (30 sec emergency whistle recall), play (usually tug-o-war for 5 mins), training (command based for 5 mins), and crate/nap (15 mins - 1hr).
• mental enrichment like a puzzle, sniffing game, or shaping exercise 1x day.
• impulse control training using leave it, drop it, and stay commands. ***however, something else I had recently added to his routine to help with his impulse control: 3secs delayed reward in sit command, when I bring him his water/food I make him sit before I place it down in front of him - if he lunges at all I stand up completely and then start over again - and when I let him out of his crate I make him practice stay for 3secs; when I discussed this with my other dog mom friend she said that this was too much for a puppy and I should eliminate these aspects of his training until he is a lot older.

I also want to note I don't feed him on a schedule or in a food bowl. He gets water throughout the day, jackpot treats for his emergency whistle recall, a treat for a big training milestone, and his kibble is given to him throughout the day as training rewards.

What should I do?