Using the set files we prepared will ensure you test the EAs with the same exposure and you won’t lose more than 1% of the account if the SL is hit.

If you trade with the 8 EAs at the same time there is a chance that you will exceed the Daily Loss with some challenges.

That's why it's not a good approach to trade on a Challenge with all the EAs at the same time. You better test them on a trial/demo and select which one to use in a Challenge.

This is how Petko Aleksandrov manages the EAs:

For more information check this Forum Topic.