Well the Ravana definitely looks and seems like it's made for blitzkrieg tactics (what in BP is called a shock-jump). And it demonstrates those tactics in The Great Hunt. It could very well be the Ravana was intended by the developers as a fragile, but powerful blitzer, designed to destroy ships quickly and jump out. More like a howitzer than a tank, if you will. Given that skill-set I could see how a corvette and a SQUADRON of bombers wouldn't really have a problem taking it down.
In game however, that aspect of the Ravana isn't mentioned. It's presented to be the successor of the Lucifer, essentially.
It really does only take minutes in game, even on Insane. Your wingmen will all be dead, unless you manage to lead them to the corvette and tell them to defend it.
The interceptors from the Ravana are frustratingly distracting, and they will kill you, but it's perfectly winnable. In fact, as I said, the corvette can win itself. If you're really having trouble in that mission, and you aren't being a kill-whore, just cover the corvette.