This is a very good point, but I think the Japanese way might actually be better. The problem is that emphasising brutality and ugliness in the style of the Culture may over time lead to a shift in perception normalising agression, or in other words, it could shift the Overton Window towards militarism. For example, if ships were named something like "Peacekeeper" or "Ambassador" rather than "Torturer" or "Thug", it would lead to a perception of peace-keeping as their intended role.
It works in the case of the Culture because of their extraordinary degree of self-awareness and anti-militarism; no member of the Culture could possibly lack cognizance of the significance of the names, wheras we, alas, live in somewhat less enlightened times. In the Culture it serves to emphasise the ugliness of their purpose, wheras if applied in our world could be all to easily misinterpreted as unvarnished militarism.
It is interesting to note the degree of anti-militarism in Japan. Though this may be taken to an extreme in the opposition to taking part in international peacekeeping missions, at the very least it means that Japan is very unlikely to be subject to escalating influence and dominance by the military as may be permitted in other countries due to general public apathy. However, I think this also means that any attempt to emphasise the inherent ugliness the the purpose of the military would be prima facie faced with extreme opposition, no matter the intent.