User blog comment:Mexican215/So who was satisfied with the last battle against the Reapers?/@comment-4967682-20130213023320/@comment-24174486-20130213211855

"How can combat make the crucible which requires scientists and workers make it work when the combats only involvement is in the final battle."

Fleets and soldiers fight off the Reaper forces which might otherwise damage the Crucible, thus impairing its functionality.