There's a lot of difference in the number of points required for a first time runout:
Post Needed 1,2,3 7 4,5 6 6,7 5 8 4
So, you could say that 8 has the best chance for the runout, but ...
... everyone knows that and may adjust their bets.
With the other posts, it takes more points, but they play sooner and, if they're gonna run out, they'll beat 8 on the way.
The supporting cast of Place/Show finishers changes, too, depending on which runout you're planning.
So, which one do you like? Let's keep team ratings out of this - look at post numbers only. Don't forget to give us the reasoning behind your selection.