Colossus 217 Titan

Not sure about the first one, how sure are you about those letters?

caveman

Thank you.

186a H?S?E?S
178d Wood Slivers - sHavings as first letter.
161d Scrutinising - asSessing as third letter.
162d Yankees - amEricans as fifth letter.
179d Attackers - aSsailants as last letter.

The best I can come up with is hoaxers. This would mean that assessing is incorrect but I don't have the magazine so I don't know how much that would mess things up.

That was really helpful. Appreciate it!