Hi Angelo,
I do not know of the 2 options your are referring too as you have not linked them here so I can review them. What I have seen Petko do in some of his videos is he will compare all the Backtest Output results for both M15 and H1 and chose the one with the best overall Backtest Output results. This could have been what he did in the 2 options you are referring too.
If you can link the 2 options to this reply maybe I can give a better answer.
Alan,