I don't get why として is used instead of を in this sentence, as it doesn't seem to fit with the "as" sense that I know.
What I understand is this:
Treating コソアド as a group, regardless of their part of speech, is common.
Thinking while writing: I was assuming that として was related to 扱う. But if instead it is related to 一括して then Yとして一括して would mean by grouping them as Y.
Which would mean that something like それを would be omitted in the sentence
It is common to treat (コソア and ド) by grouping them together as コソアド.
Am I correct?