paper and dice? Like the old "Stellar Conquest?" Cool. Nice cover. Agree about the two ships looking identical in shape, size and orientation on the page.
For another cover, may I suggest going forward from your first cover. Perhaps have one of these 'human' ships facing off with an 'alien' ship, both in orbit around (or near) an earth - like planet with two moons? Use contrasting colors of the ships. Create visual tension.
Are they, or will they be friendly? or not?