Thank you for the comment, Sharpes, as well as the thoughtful suggestion!
The map continues to drift unfinished at this point, though we have the calligraphy finished and we know how to proceed. We just need to find the time for it. The Vagabonds game itself has been taking up all of our free time. We are currently near completion of the next (and hopefully final) draft.
The Edo period is much, much different from the 14th-16th centuries (roughly the Sengoku period). Shogun: Total War, for example, is focused around the Sengoku jidai (creating a war game in the Edo period would be incredibly boring). Vagabonds is all about shattering the samurai-centric perspective of Japanese culture and history.
That being said, creating a map of the Sengoku period with the information you desire is not impossible, but it would be an immense challenge. The information is available, just not necessarily in English. The target map would have to be huge, otherwise it will be cluttered. You might want to pick a specific conflict, or a specific two clans to focus on for the 200 years you wish to document. The Uesugi vs the Takeda come to mind, and there's a good deal of information on that if you're willing to go to the library. Also, the folks at Samurai Archives are friendly and knowledgable, and would be willing to help you. One fellow there is particularly interested in the particulars of samurai warfare and military doctrine, if I remember correctly.
You'll also find a bunch of maps showing what clan occupied what territory in a given timeframe. These tend to be accurate, but in a general sense. Political boundaries were not very elegant during that time, for obvious reasons, so most of those borders are approximations. Additionally, the power, prestige, and influence of a daimyo was greatly dependent on his connections, in addition to (sometimes rather than) the amount of land he was in control of. That's why Sengoku period maps can be confusing; you'll have a family simultaneously "controlling" two domains on the opposite side of a province, or even an entire region. If you look at a lot of non-European, authentic Japanese maps of the time period, you'll often see labels rather than borders to show political power or influence.
Good luck to you!