Short.....
My guess is that the 7 - 10 color would have more vertical travel in the water column as the boat speed varies and your direction changes (turns). So I think a 7 - 10 color lead line would catch more fish..... but it depends on the day and the fish too. If you just so happen to have a high concentration of fish right where your "3 color plus torpedo" is running, it might take more fish than a lead core line.
I've never run torpedos, but do fish leadcores...... so I might be biased.
Run the experiment, and let us know!