Why Guided Dialog Policy Learning performs well? Understanding the role of adversarial learning and its alternative. - Sho Shimoyama; Tetsuro Morimura; Kenshi Abe; Toda Takamichi; Yuta Tomomatsu; Masakazu Sugiyama; Asahi Hentona; Yuuki Azuma; Hirotaka Ninomiya (CoRR, 2023)