[madhadron]

The ACM should probably have run this by a statistician before publishing it. As another commenter pointed out it opens with bad experimental design, then goes on about random allocation in a way that makes it clear that the author doesn't understand the subject well.

You don't need sequences of independent samples for assignment. You need sequences that are independent of the sequence of subjects being assigned. If you have a very small number of possible sequences then you can't get independence by the pigeon hole principle, but both 2^(64*N) (from N random 64 bit numbers) or 2^64 - 1 (for N samples from a PRNG) are so large that it doesn't matter.

The argument about a sample of seeds not producing a flat histogram is also weird. Of course it doesn't. That's irrelevant to whether uniformly sampling a sequence of N 64 bit numbers from the space the PRNG provides produces independent sequences from the subjects.