just remember to 1 or 2 lvl 6 caps is far better than a fleet of lvl 1 caps. i often go whole games as vasari with only the egg, let my egg be greedy with exp and divert the costs of another cap into 5 carriers or some armor and HP upgs, or for that matter trade ports
also consider i prefer to rush so i often scrap my cap factory. so to buy 2nd cap i need to build a new fac, upg tech for capitol ship crew possibly fleet cap and pay for the damn cap itself. thats a lot of time and funds, not to mention the benefit of multiple caps youll find the more you play isnt as great as it looks on paper. (for vasari that is, i like 2+ for tec and as many as 4 for advent)
of course its all situational and you have to make decisions as the game pans out and the map gets scouted, so sometimes differant approaches will be more effective, use our advise and rely on your personal experiance most of all