It is ........... that giving too much detail may actually be confusing.

'Arguable' means open to debate, dispute, or not clearly settled. The sentence suggests that the idea that too much detail might be confusing is debatable or could be argued either way. 'Astute' means clever, 'atrocious' means terrible, 'awkward' means uncomfortable, and 'attached' means connected - none fit this context of presenting a debatable proposition.