So I was slightly off earlier. I sat down and worked out the forces involved. Worst case is the clip will have to sustain a static load of 3x the line tension load (assuming you're using a dutch clip in the typical way everyone rigs it). So for a 200 lb line tension, the clip could see a static load of 600 lbs. Bear in mind that is just a static load - the dynamic loads can be way higher.

I think RainMan's rule of thumb of having every load bearing element in a suspension system rated to 2000 lbs is a very good one.

Just my two cents.