OHKO moves are regarded as niche in BSS (the format you're playing), and probably not the sort of thing you want to base your whole game around. They're either too inaccurate, or take too long to set up. Their main utility is as a nuke for Pokemon that are prone to being walled.
You will not win games with the strategy you have devised, as you cannot plan competitive Pokemon games to that extent. It is good to have a game plan, but it needs to be adaptable turn-by-turn, and less one-dimensional.