We should always bear in mind that any pathogenic agent, including antibodies or miasms are acting up on an existing constitutional biochemical background, determined by the individual's specific genotype-phenotype combination.
The constituent molecules of causative factors creates the original molecular inhibitions in some or other biological molecules in the organism. In most cases that would be similar in almost all individuals affected by that particular causative agent. Any such molecular errors have a cascading effect in the organism, by the way creating new errors in new channels. When a biochemical pathway is blocked by a particular molecular inhibition some where, the accumulating metabolites may create new molecular inhibitions. That is expressed through different 'trains' of symptoms.
Same pathogenic agent creates different types of cascading of molecular errors and associated trains of symptoms.
We will have to prescribe different drugs to remove all molecular inhibitions happened at different stages of cascading, especially in chronic diseases. Nosodes and other drugs selected on the basis of causative factors, can only remove original molecular blocks created by pathogenic molecules, not the cascading molecular errors that appeared later. That would require other appropriate indicated drugs selected on the basis of similarity of symptoms representing the molecular errors.
Cascading of molecular errors can be compared to the phenomenon of simple traffic block somewhere in a city cascades into a complete breakdown of traffic system in the whole city. A block in one junction leads to consecutive blocks in feeder roads and adjacent junctions, and gradually brings the whole traffic to standstill. If we interfere during initial stages, we can re-establish traffic by simply removing the original block. But when the whole system is broken down, you cannot re-establish traffic only by removing original block. We will have to intervene at different points in the city to resolve the problem. Same with difference in dealing with diseases at initial stages and later stages.
Here lies the importance of 'similarity of symptoms'.