Can maws eat "real" starships? If so, I don't really see an issue with this per-say, though the balance of the maws might need to be double checked keeping the ability to swallow starships in mind.
If they cannot eat "real" starships, then there is a problem. If expensive, low cap units of one class of ships cannot be targeted by them, then presumably there is a good balance reason for it. Because many of the low cap spire fleet ships are balanced like starships, the same reasoning should apply to them too.