Only +Stats plan relies on being continuously lucky enough to not roll for an strong enemy. That's almost certain to cause us to prematurely use FOR and get in the exact same situation you warned against.
The Main goal here should be decreasing the amount of time we are forced to solely depend on FOR. Wait and Hope accomplishes that by saving Arete, strategizing and figuring out if a path of retreat is possible. We can safely grind after that, when we invietably come face to face with an enemy mightier than us, we can use the resulting picks to get an 7 Arete option, hereby making us capable of not depending on FOR alone. That's how we snowball without taking undue risks.
The only difference between this plan and picking off stragglers is a measure of patience. One gets into grinding right away, the other waits, and prepares before jumping straight into action.