When doing the run animation for a character, do animators know in advance what the run speed will be in-game so that they can make the animation in Maya (or any other software) to match that speed (and make sure the feet stay in place etc)? Or do they just do the animation in maya, make it look the way they want, and then match the speed in the game to that animation?
I know the question is not specific to Unreal, but anyway…
I personally set a speed in the engine + I adjust the run animation in the 3d program so that it fits to the speed -> because I always create the gameplay elements first (jump height, walk speed,…) and then I adjust the anims 
More important than speed is matched sets at X number of frames. With a matched set it’s super easy to change the animations scale, make it faster or slower, in the animation BP.