While six defense counters is a lot, it's not as bad as it looks because the battle itself is going to be adding a bunch of 2/2s to the battlefield that can help defeat the battle, meaning this should be one of the easiest battles to flip in the mid- and late game
The ceiling on it is arguably above Lingering Souls but it is a lot less convenient to setup in getting there
Some things could be tweaked to make this deck even more unique or powerful, and I'd love to see your deck lists below
His Slimefoot, the Stowaway deck eschews sacrifice themes to go all-in on Saprolings
Krark, the Thumbless 50% of the time, it works every time
Maralen, Fae Ascendant Maralen, Fae Ascendant benefits heavily from getting to cast spells without paying their cost, and the main other requirement is to play creatures of two great typal builds