It was something of a rhetorical question. The point was that if everybody (including Jesus) spoke Greek, why do we find Aramaic transliterations and Semiticisms (this too is a rhetorical question; I don't agree with Casey on many points, but in his two SNTS monographs on the underlying Aramaic of Mark and Q, I think he sufficiently demonstrates that clearly Aramaic was an integral, fundamental, and essential component of the early Jesus tradition). I also find Emanuel Tov's work to be quite solid. I have also found that the scholarship has tipped in favor of perspectives/views such as Chancey's:Because the reader / hearer did not understand Aramaic. All of the Aramaic in the NT is translated - and I believe transliterated (Greek letters for Aramic words).
Chancey, M. A. (2002). The Myth of a Gentile Galilee (Society for New Testament Studies Monograph Series Vol. 118). Cambridge University Press.
Not that you need to or haven't already, but see also e.g.,
Vonder Bruegge, J. M. (2011). Mapping Galilee: Josephus, Luke, and John in Light of Critical Geography. (Yale University, Doctoral Dissertation).
Chancey, M. A. (2005). Greco-Roman Culture and the Galilee of Jesus (Society for New Testament Studies Monograph Series 134).
Freyne, S. (1980). Galilee from Alexander the Great to Hadrian 323 BCE to 135 CE: A study of 2nd Temple Judaism (No. 5). M. Glazier.
Grabbe, L. L. (Ed.). (2001). Did Moses speak Attic?: Jewish historiography and Scripture in the Hellenistic Period (Journal for the Study of the Old Testament Supplement Series No. 317). Sheffield Academic Press.
Johnson, L. T. (2009). Among the Gentiles: Greco-Roman Religion and Christianity. Yale University Press.
Kovelman, A. (2005). Between Alexandria And Jerusalem: The Dynamic of Jewish And Hellenistic Culture (The Brill Reference Library of Judaism). Brill.
Root, B. W. (2009). From Antipas to Agrippa II: Galilee in the first-century CE. (UCLA Doctoral Dissertation)
Savage, C. E. (2007). Et-Tell (Bethsaida): A Study of the First Century CE in the Galilee. (Doctoral Dissertation).
van der Horst, P. W. (2006). Jews and Christians in their Graeco-Roman context: Selected Essays on Early Judaism, Samaritanism, Hellenism, and Christianity. Mohr Siebeck.
Young, I. (2003). Biblical Hebrew: Studies in Chronology and Typology (JSOT Supplement No. 369). T&T Clark
etc..
I have found that the archaeological studies and the scholarship on these (among other things) has made positions that are exemplified in popular literature by Crossan & Mack (among many others) obsolete.