Probabaly already made you throw some very good systems in the dustbin and made you try losing ones.
Look do the test, take your EA run it for a week, then back test the same week. Compare the results. If you can run it on a second broker.
You'll end up with three sets of results.
You just can't build a future on that. And you're wasting your time trying.
My advice to you. Test live, you see very quickly if you like the system or not.