Gond is a brief section, and the proportion of it occupied by poets from outside the Sikh succession is conspicuous. Kabir and Namdev both have a substantial presence here relative to the section's length.
That proportion is the interesting fact. In a volume compiled by a Guru, for a community forming around the Gurus' teaching, there are headings under which the majority of the material is not by a Guru at all. Nothing marks it as secondary. It is not appended at the end of the volume, not set in a separate part, not annotated to explain its inclusion. It sits under the same heading, in the same order the arrangement prescribes, and is sung in congregations the same way.
The editorial principle behind that has to be inferred, because the volume does not state it. What can be observed is what was and was not admitted: compositions that accord with the teaching were included regardless of who wrote them or what tradition they belonged to, and compositions circulating under the Gurus' own names were excluded where the compilers did not accept them. Authorship was neither a qualification nor a disqualification.
Sections like Gond, where the arithmetic is visible at a glance, make that principle harder to overlook than the long sections do, and they are worth reading for that reason rather than being passed over for their brevity.