What little we know about Husbands 1, 2, and 3 comes from things the Wife tells us about them, so we can't actually analyze their characters, but only the Wife's description of their characters. According to her, they were three of a kind: "goode, and riche, and olde" (203) – so old, says the Wife, that they had trouble having sex. By "good," the Wife probably means easily dominated – according to her, they quickly bowed to her authority after she accused them of saying derogatory things about women while drunk. After that, says the Wife, they were just happy when she spoke nicely to them.
The presence of her first three husbands in her Prologue serves the Wife's purpose of describing the "wo that is in mariage" because of how badly she mistreats them. It also provides the Wife with an ego boost because of how easily she claims to have dominated these men.