actual_RS i just use placeholder like if the horse runs 1st,2nd,3rd then i marked it as "Pace".

I think there is no an absolute answer to this.

One more thing is you can easily observe there are some horses (like TIme WARP) which are very certain to rank 1st in 1st section. But it is difficult to guess which horse will be the 3rd, 4th,...

So when you try to predict "run style", maybe to group to target variable before training

Happy to Discuss!