[c.shu]

In my opinion you have to look at the point values here. Both scenarios you are scoring a similar amount of points if all goes well. So then I factor in consistency.

2 stacks of 6 w/ bin (42 pts); 75% of the time:
(42 + 42) * 0.75 = 63

2 stacks of 5 w/bin (36) and 1 stack of 5 w/o bin (10); 97% of the time:
(36 + 36 +10) * 0.97 = 79.54

I will leave it up to you to decide if those extra 2 points for 6 stacks is worth losing the consistency.