Here’s a link to a Harvard Business Review article about “Managing A Team Of B Players.” https://hbr.org/2015/07/how-to-manage-a-team-of-b-players
I’d caution against the labeling of individuals and teams as A and B. My experience leading hundreds of teams, strangers with little or no climbing experience, who have the vision/dream/goal to climb the Grand Teton, at 13,770′ is the highest mountain in Grand Teton National Park in Wyoming, has taught me that individuals who I’ve seen as challenged or limited often rise to the occasion. This is done in part through great leadership, incorporating some of what you suggest, especially the feedback.
As a leader, being highly encouraging and positive has gotten many teams safely up and down the mountain. Additionally, working with individuals challenges by giving them tasks they are capable of completing, is key. For example, if someone is having trouble belaying, preventing a slip from becoming a major fall with the rope, I put them at the end of the rope team, where belaying is not needed.
And when someone demonstrates good leadership skills I exploit it by putting them in the middle of the group. That way when I’m up front leading the team up the mountain I have the peace of mind that someone will deal with challenges (“rope spaghetti”) and fix it before it becomes a major issue.