You are correct.  I had not noticed how significant the pre-depletion bonus was.  Your post paints a much better picture of their playstyle than most of the older ones I have read.   On that note, are the cravers ever capable of building higher tier structures?  Their playstyle suggests that you are constantly rebuilding the lower tier buildings in each new system and by the time you have completed those buildings/ships the system is near depletion.  If this is true to any extent, then I would assume the cravers focus more on a few important buildings before pumping out ships?  On a side note,  is there ever a reason to stop a planet from depleting.  For example, keeping around a powerful enemy capital that you have conquered?

If you are playing your first game as cravers, you probably didnt notice that their non-deplted planets give way more resources than other factions. Dont think about depletion as a malus, but as an insanely strong bonus before the planet is depleted, with a cost. As a craver, you cannot really save your planets from depletion, so use the depletion for its best. For instance, in early, deplete a productive industrial planet give the opportunity to build a strong fleet or/and a wonder on this planet faster than any other faction. Later in the game, it's harder to build some very precise plans around depletion, but still, depleted planets give you the opportunity to stay ahead of everybody, if you are able to never stop your conquest. When you have 50 cravers pop, your empire gain a bonus getting better every depleted planet you own. So, depletion make you even stronger.