I'd always thought the Coalition as first presented, whilst what they did/do is as written, it was presented as a "This species on greeting others mate, it's their version of a handshake ..." which made it all the more horrific rather than just having them as rapists 40k Genestealers. I always wanted more about them ... but with things changed quite a bit. IIRC weren't the first crew to come across them ultimately killed in the greeting? Some of the Coalition are physically very imposing etc?

Been a while since I've read any Trinity stuff but back in the day I was the Trinity...