Although the tokens enter the battlefield attacking, they were never declared as attackers
For example, if you cast Junkblade Bruiser (a creature with a mana value of 5 and an ability that triggers whenever you expend 4) by paying its full cost of five mana, you'll already have spent four mana on spells before Junkblade Bruiser enters, and therefore its ability that triggers whenever you expend 4 won't be able to trigger at all that turn
Brotherhood of the Fire Fist - Swan Type Fusion Monster Attribute FIRE Typing Beast-Warrior Level/Rank 8 ATK 2600 DEF 2200 Archetype Fire Fist Typings Fusion / Effect TCG Date 2019-08-22 OCG Date 2020-10-03 Card Text 2 Beast-Warrior monsters If this card is Special Summoned: You can inflict 200 damage to your opponent for each "Fire Formation" Spell/Trap you control
Too bad the damage cannot go above 5800 without an ATK-boosting effect
Its a more useful addition to the 99 than utilized as a Commander
The second level nets you two cards, while the third level pays you off in +1/+1 counters every time you draw a card