FM development - maximize their potential

[Ksifos]

so basically he was never used to conquer a city ? all my generals have to enter cities in siege total war :\

There is no "city effect" at the turn your FM conquers the city and enters it.Only if he stays a whole turn inside he becomes affected.At least that is what happened in Vanilla.

[vollorix]

Some effects, traits, and even ancillaries, iirc, are not tied to 100% movement points ( stayed in town for 1 full round ), but to 75% or smaller number.