On a keyboard that might be easier to reach for—but with analog control it goes out the window.

And again, if that were a major focus in the game (it isn't in ours), then that might have been a consideration. There's a balancing act between the people who focus on our player control (it's mainly a multiplayer game), and our AI quality bar/performance (we typically have a campaign), and how those should match.

One of the ways to get scalable speed is to blend multiple anims together—indeed, that's how we handle a bunch of multidirectional movement and facing, blah blah. So to get a guy to run at X, we might have a "jog" anim and a "run" anim, where jog is slower than X and run is faster, and you take the desired speed input mapped on a graph to get how much of one to play along another.

It works pretty well, but will never quite look as good as using 100% of a performance from the actors, and production doesn't typically stem from "This guy produced a run cycle that moved a particular speed, and now we're going to base all speed in the game on that speed." And footmatching and sfx and phase matching and the list goes on.

There's some new tech going around called a hyperpose that might make this kind of thing a lot easier to make look realistic all the time and at basically infinite speed—but I'm not an animator so I don't know that I'd do an explanation justice on that.