The key card is present but its support is thin.
Prioritize useful support such as Knight Luminary or Gravpack Monoist.
Warp Knight Luminary to leave a Soldier behind. On a later turn Comet Crawler can sacrifice that body when the lifelink attack is worth more than a spare blocker.
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.
Sacrificing a creature is not free merely because it is a token. Keep enough bodies for safe attacks, Focus Fire and defense.
The support is missing
Favor independently useful creatures and interaction if the narrow support does not arrive.