I just tested it approximately 20 times again to be absolutely sure: and in the latest test, the griffins finally attacked the marksmen!
I won't calculate the probability of such an unlucky griffon attack; I'll just say that I've known this trick of taking cons with similar methods for about 2 years (plus or minus half a year). During this time, I've taken cons (most often minimal ones for ramp on 113) countless times. They have never attacked the archers definitively.:smile32: