His abilities are straightforward, reward natural gameplay patterns, and reduce punishment for mistakes by replacing lost Zombies with cards and tokens, which makes early deckbuilding and gameplay much more forgiving
In Pioneer, Greasefang, Okiba Boss is a prime target to return, helping the powerful yet somewhat fragile combo deck have an easier time beating cards like Rending Volley
I think the latter approach is better supported
Though its only a stat stick, it has so many stats (and a soup of keywords) that your opponents better hope they can deal with it outside of combat
Opponents would need to have a high damage-dealing character on the table, ready to challenge, or a card like Along Came Zeus to deal enough damage to banish Robin Hood, Daydreamer
Amass no longer inherently makes zombie tokens