Forgive my ignorance, but are the Lorath an enemy of Yamatai?
Another matter is that manually piloting a Yggdrasill in an area it is meant for, close-proximity debris, wreckage, and asteroid fields, can be difficult, and even going on automatic is still a good way to cause vertigo if they lack experience. It's not something one can just pilot right away at maximum efficiency. Toshiro still has work to do, though he is adjusted enough to not get vertigo, and can even pilot the ship manually if needed. A person trained in Vampires can likely pilot the Yggdrasill...until they try to use some of the less conventional systems, like the Dynamic Thruster System, the Grapplers, or the Pulsers.
It's not just the ship, but also the pilot. Not only must they be able to take moving swiftly in any direction, but they must also be skilled in the custom applications of the vessel's systems.
Finally, Toshiro designed the Yggdrasill to preserve life, as well as to honor his older brother's memory, and would find it difficult to build it as a primary tool to end life, so getting a Yggdrasill from him might be hard if he questions the motives of the person requesting one.
This doesn't mean it is impossible for the Yggdrasill to be made for others, but this early on, it may be harder than some other vessels, especially since only one person has made one. This may get easier in the future, though, so who knows, maybe you will have that fleet of Yggdrasill one day. Also, it may be at least in part for the moderators to decide if Toshiro keeps holding exclusive power over the Yggdrasill line or if it is made open to others. ^^
Edit: Bonus pics, because two-tone blue is dead sexy. This one is labeled SRCS-0XX, "Kenichi".
