Hearn is a mastermind. AJ had some tougher moments against Taam, while never being in real danger, nevertheless he is sparring with the man who gave him a few good moments. That's dedication to become a stronger version of himself, mentally and physically.
Here is the video of Eddie organising Takam sparring Joshua. Parker is really at a disadvantage, more than he already was. This content is protected
Yeah that will really make him a stronger version of himself mentally and physically, sparring a guy that was nothing more than a durable punching bag for him when they fought.
Never hurts to get quality sparring. While Takam wasn't competitive he's durable which means he'll hang in there during the sparring and Joshua had trouble pinning him down with his in and out movement. One of Joshua's biggest flaws is his foot work and working on how to cut off the ring may help vs Parker, if Parker does decide to box like he says. Will also help against Fury if that fight ever gets made. It's always good to see a fighter focus on minimising their flaws and trying to overcome them, it's the only way to become a more complete fighter. Too many boxers just focus on their strengths and then get found out when an opponent picks on their flaws.