Is "canonical exegesis" too difficult?

Christopher Hays, in a review of Childs' The Struggle to Understand Isaiah as Christian Scripture, has the following to say about the difficulty of doing the kind of exegesis Childs called "canonical":

The intellectual entrance fee for writing good theological exegesis must be very steep. If Childs or his heirs want to claim an elevated status for their project, that ambition should come with an even higher standard of training and preparation than “mere” historical-philological scholarship. Childs certainly met any standard that anyone could set, but not every theological interpreter does. He once called for a “single method” comprising both dimensions of the text, but it is here that his omission of 20th century theologian-exegetes is most lamentable: Younger scholars pursuing a “single method” approach receive no road map from Childs—they cannot learn, in this book, from the successes and errors of their immediate predecessors. (Nor do younger scholars who are less inclined to be sympathetic receive any constructive criticism, unless they are acolytes of Brueggemann.) 

Even if Childs had explained his “single method,” there are few who can and will ever master all of the necessary skills. It may be that the array of tools one needs to conduct theological biblical criticism is so extensive that canonical criticism is not really a young scholar’s game. How then could theological exegesis be carried out without requiring one person to master both biblical studies and theology?[*] 

I appreciate the final question. I'd say that one must strain to master both. Perhaps the solution to the problem lies in the way that university/seminary curricula are structured and integrated? Can they be adapted so that future students can receive the foundation they need to go on and wrestle with the "substance" of the text?

[*] "Bard Called the Tune," JTI 4.1 (2010), 151.