I dont mean sevants in general. Gil is a special case and i got my information from the type moon wiki it self and here is an excerpt from it 
"He is influenced by the era in which he is summoned, causing his blood as a human to stir and gravitate towards that of the humans of the era.[5] The consumption society of the early 2000s sullied his property, the world, so he is in a worse mood overall. Even with his personality, Gilgamesh was able to blend into the society without a problem.[8] While he will always retain his core self-centered traits, he will be more stable and like he was in life when summoned in a place without any alteration like the Moon Cell.[10] He is quite different between the Fourth and Fifth Holy Grail Wars due to his priorities. He simply enjoys the events of the Fourth, but the Fifth is utilized to fulfill his goals of making humankind worth governing and coercing Saber to become his bride. Kinoko Nasu describes the variation in his personality as the "prideful Boss King of Heroes" and the "not very prideful Horny King of Heroes."" -[url=http://typemoon.wikia.com/wiki/Gilgamesh]

Also as squall said this is and alternate version so society could be diferent from how it was in the original stay night