Final answer:
The expedition led by Fray Marcos de Niza did not have a single most valuable member documented as being crucial to its outcome. In comparison, conquests by Cortés and Pizarro included key figures such as Malintzin, who played a vital role in their successes.
Step-by-step explanation:
The expedition led by Fray Marcos de Niza, a Spanish priest, did not have a singularly most valuable member highlighted in historical records. The expedition is often noted for its attempt to find the mythical Seven Cities of Gold, or Cíbola, which ultimately proved unsuccessful.
Fray Marcos de Niza's exploration is, however, a minor footnote compared to the conquests and colonization led by figures such as Hernán Cortés and Francisco Pizarro.
Both Cortés and Pizarro had individuals who played crucial roles in their own expeditions; for instance, Cortés was assisted significantly by Malintzin (La Malinche), whose role as a translator and intermediary was essential for his dealings with Moctezuma and the Aztec Empire. S
imilarly, Pizarro, known for founding Lima, Peru, made his mark as one of the Spanish conquistadors who sought and conquered empires in the Americas.