The key card is present but its support is thin.
Prioritize useful support such as Fortress Kin-Guard or Trade Route Envoy.
Give Kin-Guard a counter when its larger body is useful, then Envoy can draw on entry. If you need more bodies instead, choose a Spirit and find counters elsewhere.
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.
Endure forces a choice between size and the token. Do not count both outcomes from one trigger, and do not weaken early plays to chase a third color.
The support is missing
Favor independently useful creatures and interaction if the narrow support does not arrive.