The documentation for eldev-before-loading-dependencies-hook says that the 2nd argument received by hook functions is a list of additional sets, but in practice this argument seems to just be a single symbol.
Also, more generally, the convention for hook naming is that hooks that receive arguments should be named ...-functions instead of ...-hook. (See the section on hooks in the Emacs manual.) You might want to consider renaming some of Eldev's hook variables accordingly.