With +Jay Steven Anyong and Chester spearheading a Living L5R campaign here in Metro Manila, I have been tapped to GM the adventures of the Mantis Clan. It also gives me a reminder to return to this idea, so let's get straight to the task at hand!
To recap, the goal is to tweak the concept of the Mantis Clan by drawing more heavily on Southeast Asian (SEA) societies. The closest analogs would be the maritime, pre-Islamic mandalas of the 13th Century. Majapahit is a very good peg. But I am a biased Tagalog so I will likely draw as heavily (if not more so) from Filipino examples.