This race looks like a prelude to something much longer.
The 6 has beat the 3 3 x, lost 1x; the 1 has beaten the 3, 6 and 5, but usually at longer distances. The 2 looks like the new blood here.
The six ran 137.0 and 137.1, both times running 1-1-1 and the 2 has run 135.6 and 136.2, running 3-5-5 and 2-2-2.
The 2 and 6 are my picks.