Neil Godfrey has made chapter 7 of Thomas Brodie's recent book, Beyond the Quest for the Historical Jesus, available online. It provides a wonderful illustration of the sort of forced parallelomania that I recently parodied.
There might perhaps be an allusion – whether by Jesus or by the Gospel author – to the stories about Elijah and Elisha in 1 Kings 19. A phrase like “I will follow (after) you” [ἀκολουθήσω ὀπίσω σου in the LXX, ἀκολουθήσω σοι in Luke] is hard to avoid in a context related to discipleship, and is scarcely a clear indication of dependence, or even deliberate allusion. But even if one hears some echoes of those earlier stories in Luke 9, Brodie tries to force as much material as he can into the mold of literary transformation of that portion of the Jewish Scriptures, no matter how slim the connection or how awkward the fit.
All this may perhaps seem plausible to some. To me, it looks like a sort of Biblical connect the dots.
There is a longstanding Rabbinic tradition of exploring the additional meaning that surfaces when two texts which feature the same keywords are related to one another. It has always been possible to relate texts in this way, and the ability of interpreters to do so scarcely means that, in all the instances where this has been done, what we are dealing with is one literary text that was created entirely by a reworking of the other. The same words appear over and over in countless texts, and not all of them are connected. The ability to see such patterns more vividly than others may be indicative of a beautiful mind – but whether it is a healthy one is another matter.
The question of literary allusion can be a highly subjective matter, and those who seek to make sense of texts need to be cautious – as do those who would make sweeping assertions about ahistoricity on the basis of similarities that are, at best, slim and superficial.