Compatibility with Eternal is planned for when the project reaches the appropriate stage (i.e., when there are games on the map, not just duels). In any case, as I already wrote, especially on large maps, playability will be present even WITHOUT active AI resistance, simply because the player (on a high difficulty level) will be competing with neutral creatures. Every week on such a difficulty, the number of neutral creatures will double, which means that if the player plays slowly and not efficiently enough, they will lose (be unable to win) simply because they won't be able to defeat the necessary neutral creatures in time. Since they will not be able to double the power of their army every week, the relative growth rate of their army and its strength will slow down significantly over time. And they will be forced to break through as quickly and efficiently as possible, capture cities early, hire additional heroes and new troops, etc., in order to complete the objectives before they become impossible. Thus, for a competitive (sporting) element, AI is not necessary. It will be possible to play maps without any active AI participation at all.