Ushakov wanted soldiers for Corfu because his sailors possessed expensive skills that the fleet still needed. He could have used them ashore, but preferred to avoid losing trained seamen in land fighting when soldiers were available. Shipboard combat, a quick raid, and a pitched land battle demand different skills. Officers can fill unfamiliar roles in an emergency, yet a specialist opponent of similar ability has the advantage of training and experience suited to that environment.
Notable Point · 2:58:19-3:01:28
Why Ushakov sought soldiers instead of spending sailors ashore
The siege illustrates why trained sailors and soldiers were not interchangeable manpower for sustained land combat.