I'm not interested in any one to one personal disagreements, least of all hostile ones, but have long been very interested exploring the topic (and think it is of relevance to wide audience here) --
Docherty's book is a great intro to the Second Temple literature and an overview of the scholarly views on its respective documents, published 2014. What is of interest is the broader insights the book crystalizes for anyone curious about the intellectual climate around the period the gospels were composed. Christian influences are an obvious question when it comes to transmission and they are best considered in the broader context of the literature as a whole, I think.
The author is kind of qualified for this task and I don't think anything is gained by dismissing such a work on the grounds that someone just wants to sell a book and because one part of it disagrees with something a favourite author wrote forty years ago:
Susan Docherty is Reader in Biblical Studies and Head of Theology at Newman University Birmingham. She is the current Chair of the Annual Seminar on the Use of the Old Testament in the New Testament, and serves as a member of the Steering Group for the Society of Biblical Literature Hebrews Section.
Milik's work was published in 1976 and much scholarly work has been done since then. The Similitudes (in Enoch, not Ezra] are generally dated from late first century BCE or early first century CE.
This book [Similitudes] is the latest part of 1 Enoch, and the fact that no trace of it has been discovered at Qumran has contributed to suggestions that it should be dated to the late first century CE and may even be a Christian composition. The current scholarly consensus, however, is that it was composed in, or shortly after, the reign of Herod the Great (37– 4 BCE), and is a Jewish composition, since it makes no reference to Jesus or to any specifically Christian themes.
Docherty, Susan (2014-09-18). The Jewish Pseudepigrapha: An introduction to the literature of the Second Temple period (Kindle Locations 2544-2547). SPCK. Kindle Edition.
Reading the overview of the various types of Second Temple literature one learns what themes and questions were of special focus throughout the periods from the Hellenistic era to the end of the first century CE -- even the generation following 70 CE.
It is more than just one of these texts that informs us of the rich variety of messianic ideas that were extant throughout this period.
My recent comment did not have you in mind, Stephan -- I don't think our own disagreement has any relevance to the larger interest of what recent scholarship has to offer. Judaism before the rabbinic period was evidently of quite a different character and that is worth anyone's study.