@Wasadar4 thanks for pointing that part out. Yes, characters were designed and written to fulfill certain plot, that is truth. That is because those characters were given a definitive role to represent the negative side of the story. I dont think the servants of FGO would be playing a similar role to Truniht, since they are only fighting for different factions and causes (like Reinhard/Empire vs Iserlohn/Yang Fleet) during conflicts and would ultimately returned to the throne of heroes after the conflicts, and to be summoned once again eventually when MC/Chaldea needs them.
If there is anything to flame about the servant would be based on their in real life lore: to the Europeans Columbus is a pioneer who discovered a hidden treasure but for the native Americans he nothing but a nightmare. But then again fans would say FGO = fictional so judging servants based on their real life lore is a big fat no otherwise a ton of them would be controversial af.
I still agree that characters are written for plot purpose and to gain the likes for different reader/player and it would be unreasonable to have every character being Likable to everyone. Some characters must have some flaws to make them standout.
I would totally NOT like FGO if every chick were drawn by Takeuchi.