Also not every A+ hard-problem team would be willing to recruit an unproven newbie who knows nothing about internal processes and lore and culture of the compan

Also not every A+ hard-problem team would be willing to recruit an unproven newbie who knows nothing about internal processes and lore and culture of the company and would require a lot of training and adjustment and handholding for a while. Why bother if they could have somebody from another team who has worked there for a while and proven themselves and knows what they need to hit the ground running? Maybe they let the newbie to clean the dojo floor, and sweep the garden, and cut the wood, and take out the garbage, and paint the walls, and so on for a while and then he learns the ropes and knows more he could find himself a team that is more to his taste.