The key card is present but its support is thin.
Prioritize useful support such as Mechanized Ninja Cavalry or Zoo Escapees.
Mutanimals followed by Cavalry creates two alliance triggers, allowing two counters on the creatures that most improve combat.
Your deck already enables the plan but is losing the early turns.
Take a castable early creature or efficient answer before a second expensive payoff.
Counters cannot compensate for an empty curve. Keep enough cheap creatures before adding another four-mana payoff.
The support is missing
Favor independently useful creatures and interaction if the narrow support does not arrive.