In addition to what jwk94 said, it is also my understanding that sometimes they may commit translation errors.
So one thing I noticed while watching Gaim was with how two subbing groups translated Ryomas name.
Nihon would always do Sengoku Ryoma but one subbing group switched it to Ryoma Warring cause that was what they were translating Sengoku into which was in their translation from the OP.
Also with the Niho sub I know I literally just said this before but they do a lot of cursing I think when is isnt needed. Excluding when a character would say ふざけんな fuzakenna but there have been times where someone would just say 貴様 kisama and they would translate that to HARD potty mouth talk.
Personally I dooooont really mind the subs at times. Im kinda used to japanese being kept in like when the arms and such were being called out.
It was dicey with Wizard and I think Ghost at times with the transformations I recall with Ghost Nihon would leave in the Japanese for some of the eyecons. They're very hit or miss at times but I suppose at the end of the day it gets the job done.