If you import a deck containing cards you don't own, there's a Craft All button by the Done button in deck edit you can use to craft all the missing cards
For example, the Bird Spirit complements commanders with Adventure synergies like Kellan, the KidKellan, the Kid and Gorion, Wise MentorGorion, Wise Mentor
The more aggressive your deck is and the lower your curve is, the fewer lands you need and vice versa
I don't yet know if the juice is going to be worth the squeeze, as any commander with flying and vigilance might rather keep those counters
Sure, we'll have to sacrifice them because of Decayed , but we'll have gotten free creatures just from them dying