Fashions in history are as subject to change as any other area, and there is a temptation amongst scholars to throw out the baby with the bathwater when the next shiny thesis comes along. History deals largely with intuitive probabilities, and so my general advice would be take everything with a grain of salt.
My particular interest is in religious historiography, especially in the Eastern Mediterranean in the centuries around the turn of the Common Era, and it's reasonable (generous, actually) to characterize the state of the Academy regarding this period as "fragmented." Ideological bias is on full display amongst many scholars of this period, and my experience of those specializing in other times and places is that they are often equally partisan.
I would suggest, always, examine the primary sources. As far as any history is concerned:
Do we know when it was written?
Do we know who wrote it and why?
Do we know what "genre" the sources are?
Do we know how (and if) the source was received at the time?
Do we know about the wider literary and philosophical context of the source?
Do we know its provenance - how it came into our possession?
Corroborative fields such as archaeology, linguistics, genetic evidence, numismatics, dendrochronology etc. can lend varying degrees of weight. Sadly, IME, few scholars demonstrate a wide aptitude in utilizing all of the tools at their disposal when constructing an historical thesis.