I suspect you can get statistical significance with fewer than 10,000 deals. Then again, computer time is cheap. The double dummy solvers that I have used (Double Dummy Solver, Deep Finesse and GIB on BBO) all highlight the cards that will produce the double dummy result, so it seems to me that a table should be able to be produced with Option 1 which would list all 13 possible leads and how often each produced the double dummy result, how many tricks on average the lead results in and how often the lead beats the contract. With Option 2, you'd want to use the same random seed for each trial, which really makes things identical to Option 1. Doesn't it?