Alternative will not be a stretch goal but part of the base goal. They will not be translating it again, but using Amaterasu's translations. Also Amaterasu's translations, despite your feelings on them, are highly criticized throughout the scene and are considered to be in heavy need of translation checking and editing by many people. Also it is highly possible that Degica would not be able to do this without Kickstarter, which is the entire point of the service in my eyes.
Also, licensing is the single biggest cost for VN translations. Not paying the translators or programmers or QCers, but paying the original license holders for the game and also the voicework. The costs for that are WAY higher than paying your staff and can get quite extreme. That's why kickstarter is needed.