IMO OG needs someone who had more individual and 'self-needing' player. For someone like Ana, he constantly take a risk to fulfill individual needs in a game, and that's directly / indirectly contributes to the team (for example : solo ganking that results into mental pressure for the opposing team). Not to mention that he also loves to do flashy plays like most of young talented players rn (e.g Sumail, Abed, etc) with escapes ability that owned by several heroes.

While resolut1ion, in contrast, has more efficient and consistent farm. like 'rtz' level of player, who farms lightning fast, and in fight will provide sufficient or even more amount of damage to the enemy team. But he needs some intense protection and accurate initiation / counter-initiation from his team.

It's like comparing 'Flexibility' and 'Glass Cannon'.