I can't see 4 vectors. I see 3 Vectors. And every Vector takes three numbers.
I looked up the SetTouchdownPoints of the stock DG and it is the same exept for the numbers.
Here the original code from stock DG
SetTouchdownPoints (_V(0,-2.57,10), _V(-3.5,-2.57,-3), _V(3.5,-2.57,-3));