Final answer:
Soldier Company and Cornish Inc. should opt for a nonequity strategic alliance to collaborate while maintaining control over their assets without the need for equity exchange.
Step-by-step explanation:
The cooperative arrangement Soldier Company and Cornish Inc. should choose to maintain control over the assets they commit while creating a competitive advantage is a nonequity strategic alliance. This type of alliance allows each company to collaborate without establishing a separate entity, and without requiring equity investment or exchange, thus enabling them to maintain control over their individual assets. The key benefits of this arrangement include resource sharing, strategic flexibility, and reduced risk compared to equity alliances or joint ventures.