Almost a puzzle game instead of a strategy game. The enemy appears to choose their fleet based on the budget of your own fleet. So if you spend less, you fight a weaker team. But the Dreadnaught at the end of the game has set stats (~2500 hp and ~300 damage per shot).
Therefore, the goal is to figure out the most efficient use of funds that has a decent chance of surviving each round. Spoiler alert, it's a Heavy Cruise with Collosal Hull and Missiles (700). You could theoretically only buy 2 and make it until the end, but the chances of getting focus fire go down with more ships. Right before the final battle buy the most expensive ships possible and it's a breeze. 