You probably could have done the same thing in one line:

    cat *.log | grep condA | grep condB | sed 'some regex to get rid of dates, etc' | sort | uniq -c | sort -nr | head -n 5

Or something like that... Not very efficient, but it would work in a pinch. I actually do something like this all the time for large datasets. In the time it would take me to write something better, this set of commands is already done.