The extra mdf edge protects the bowsprits and sticky outy bits as well, making it less likely that things will bend or snap off in the heat of action. I did wonder about using wider 30mm bases like ones I used for my Victory at Sea French fleet but I don't think it would be worth it. They look nice but only if the whole base is textured to match, as you can see in the photo below:
If not, I can always use numbers or just label the underside of the bases, which is less convenient but just as effective. I'll also have to paint the bare mdf areas with the same base colour that I'll use on the textured bases, so everything blends in rather than adding extra texturing to cover it all up. I should be able to get all of the basing done pretty quickly as a result.