A unit of 5 dark riders are charged in the front AND rear simultaneously by two tomb scorpions.

Four dark riders are killed, and the lone survivor breaks and flees. Both scorpions elect to pursue.
Which direction does the rider flee in? He's not auto destroyed by running into either scorpion as they are unit strength 4, and both scorpions are at the same unit strength, so the rider can't run from the highest. In order to resolve it for this game, we randomised it. Does one of the players get to pick? Is the pursuit towards nearest table edge? Some other resolution?