I actually think the best way to use Amass in Commander is to completely ignore the actual idea of it and use the fact that anything with Changeling is technically an Army that can be improved
Best Pricier Precons Sometimes budget can be a problem, but other times you simply have no issues spending as much as you want on a fun or powerful deck, regardless of how strong your commander is
Acidic Soil Armageddon Clock Ashcloud Phoenix Borrowing the East Wind Builder's Bane Coalhauler Swine Copper Tablet Cyclone Descent into Avernus Desolation Earthquake Exocrine Farideh's Fireball Fires of Mount Doom Flame Rift Heartless Hidetsugu Hurricane Ifh-Bff Efreet Lim-Dl's Hex Mana Clash Mind Bomb Outpace Oblivion Price of Progress Rolling Earthquake Rumbling Slum Searing Rays Slagstorm Spawn of Mayhem Spear Spewer Stench of Evil Sunspine Lynx Volcanic Eruption Wheel of Misfortune Wing Storm
Fertile Ground and Trace of Abundance come down a turn earlier, and can give you any color of mana you might need
Then, if you have 1 or more Life cards, draw 1 card and trash 1 card from the top of your Life cards
For (3)(B)(B), you get a 5/5 Flyer with Deathtouch