A companion/follower by definition is any NPC you have in your party or hire into your party to follow you around which is exactly what the Hall Of Heroes gives people.
You are clearly clueless about companions in rpg games.
They are more than henchman who only follow you around like in hack and slash games such as diablo.
They have quests, like/dislike each other, may refuse to join you because of your alignment, agree/disagree with your decisions and can even atack you because you've crossed the line.
I highly recommend you to check Baldur's Gate 2 companions to understand the difference.
