Full Idea
The 2nd standard objection to coherence is 'alternative coherent systems' - that there will be indefinitely many possible systems of belief in relation to any given subject area, each as internally coherent as the others.
Gist of Idea
For any given area, there seem to be a huge number of possible coherent systems of beliefs
Source
Laurence Bonjour (A Version of Internalist Foundationalism [2003], 3.2)
Book Reference
Bonjour,L/Sosa,E: 'Epistemic Justification' [Blackwells 2003], p.54
A Reaction
This seems to imply that you could just invent an explanation, as long as it was coherent, but presumably good coherence is highly sensitive to the actual evidence. Bonjour observes that many of these systems would not survive over time.