The GMG wont openly attack samura, that's what caused the whole mess with the last GMG faction - they declared hostility against a samura trader, told him he couldnt go through sigma 13, and it sparked a conflict between the GMG and the kusari navy/hogosha/FA.
More likely, GMG would 'tip off' the blood dragons and possibly the golden C as to where a samura transport is, so that they can take it out.