Angel of Invention solves this problem by not only being a creature herself, but allowing you to manufacture creatures on the spot should you need them
But we're talking a 6-mana chunker with no protection of its own, so if you want this to pan out, you need to have scry sources in play immediately upon resolution, or have a plan for getting Eligeth to stick
Bring Eevee and its Evolutions to life with exclusive cards and a collectible poster
This build does require you to play enchantments, but in Sultai colors you have no shortage of powerful ones that can be played in conjunction with your mutate creatures
Humans tribe has the Training mechanic that allows them to gain more power and toughness when attacking bigger creatures, and Zombies allow you to Exploit them for certain advantages
In slower pods, I like that precision more than raw tempo