My changes to the Servants

I adore the Servants classes of the Fate franchise but I can't deny that to create my Servants (and the story of Fate / Yggdrasil) I had to change a few little things, something tiny, nothing huge, but I did it just for being able to put different historical characters. Basically I modified the conditions that establish which Heroic Spirit can enter which class: the modified classes are the Saber, Assassin, Rider and Berserker classes. 

Changes:

Saber - it doesn't have to be made up of knights but also by people who have done military training, so by characters who have wielded a sword at least once in their lives.
Assassin - is not a class composed by force of "assassins" in the literal sense of the term but also by dishonored figures.
Rider - doesn't have necessarily a physical steed, real, but also a metaphorical one.
Berserker - it's not necessarily crazy. I thought of the Berserker as a class with heroic spirits who lost their way.