I mean like, you miss both cards on turn 3/4, having them collide on 5. That's pretty much worst case scenario.
In general, likely turn 3 is worse because early bad luck is worse than later bad luck.
Ah, now I get it. I (and I assume paddy) was thinking that you got one of them on 3, the other on 4, and
then they collided on 5. This would better than collision on 3, while getting
neither on 3 and 4 would be worse.
And, to answer the most recent question, I assume that collision on 3 is absolutely equivalent to collision on 4 (excluding any weirdness with other cards).