Is there any advantage to establishing two unilateral NDAs instead of a mutual NDA?

Alasdair Taylor's answer to Is there any advantage to establishing two unilateral NDAs instead of a mutual NDA? (1161875002)

In theory, a single contract can do anything that two contracts can do, and vice versa.

In practice, it is sometimes better to use two documents (eg because they are entered into at different times or are separately terminable) and sometimes better to use one (eg to save paper).