There are currently 3 slots remaining. The creature count is sufficient, so the remaining 3 slots can be anything, but they should ideally be some sort of interaction. I was thinking Selfless Spirit could be potent, as it can protect your combo and isn't too hard to cast off of Chord of Calling, not to mention Rallier can get it back.
But, that leaves 2 other slots which you ideally want to use to stop the opponent from doing something and that's where I'm not quite sure what to include.
Teardrop Kami doesn't seem like an ideal option as you have better untap creature options like Bounding Krasis/Deceiver Exarch or just more copies of Scryb Ranger (I'd probably want an extra forest or two here over the Thickets).
I'm also not sure about the inclusion of Ranger of Eos here as it doesn't really have high value taegets here besides Ballista which isn't always great without a ton of mana to sink into it.
4 Windswept Heath
4 Misty Rainforest
2 Temple Garden
1 Hallowed Fountain
2 Breeding Pool
2 Razorverge Thicket
2 Forest
2 Plains
1 Island
1 Minamo, School at Water's Edge
1 Gavony Township
1 Dryad Arbor
1 Walking Ballista
4 Noble Hierarch
2 Birds of Paradise
2 Teardrop Kami
1 Wall of Roots
2 Scryb Ranger
3 Voice of Resurgence
3 Renegade Rallier
1 Eternal Witness
1 Spike Feeder
1 Restoration Angel
1 Linvala, Keeper of Silence
1 Ranger of Eos
3 Prime Speaker Vannifar
1 Archangel of Thune
1 Reveillark
1 Woodland Bellower
3 Chord of Calling
2 Path to Exile
There are currently 3 slots remaining. The creature count is sufficient, so the remaining 3 slots can be anything, but they should ideally be some sort of interaction. I was thinking Selfless Spirit could be potent, as it can protect your combo and isn't too hard to cast off of Chord of Calling, not to mention Rallier can get it back.
But, that leaves 2 other slots which you ideally want to use to stop the opponent from doing something and that's where I'm not quite sure what to include.
It is probably much better than Linvala.
Teardrop Kami doesn't seem like an ideal option as you have better untap creature options like Bounding Krasis/Deceiver Exarch or just more copies of Scryb Ranger (I'd probably want an extra forest or two here over the Thickets).
I'm also not sure about the inclusion of Ranger of Eos here as it doesn't really have high value taegets here besides Ballista which isn't always great without a ton of mana to sink into it.
Some random value creatures that can be used as sac'-fodder here can be:
Coiling Oracle, Foul Emissary (almost a creature version of Commune with Nature), Kitchen Finks (can be sac'ed twice) and Knight of Autumn
(a multi-purpose toolbox card).
I'd probably want Deputy of Detention here as a good tutor target to remove permanents and tokens.
I'm not sure if Woodland Bellower is better than something like Sun Titan in this deck.