Just use a partially trained vollem, which any character can control without taming or lore. You can max resists on the vollem as well as put disco or other stuff on it. Much better than an untrained lesser hiryu (or boura).
That having said, I nevertheless do use a lesser hiryu on my 120 bushido templates occassionally. It puts out a bit of extra damage and you can simply ride if it gets targeted and takes damage. Also, if you are in a group with an animal healer, you can have 5 lesser hiryus on your sampire, which is very useful if you are fighting something with low physical resist.