There are several ways you can succeed.
For example, let’s say Hope has a success rate of 5%. Prayer might also have the same odds of 5%. Now multiple these two powerful forces together. Hope times Prayer = 25%?
Actually, no. It’s .25%
You might sense the sarcasm here. Though I literally have seen organizations multiply low-probability tactics and believe that overall success is more likely. As they say, hope & prayer are not a strategy.
Don MacLennan | High Tech Yankee 
I’ll go with ~10%. Still not a strategy though.
As you point out, there is certainly nothing wrong about multiplying probabilities as long as you do the math correctly. Decision making when you include probabilities is hard work and most people just prefer you to give them a “single” number. Hence the titles of books: “Why can’t you just give me a number” or “The Flaw of Averages”. Quantifying risk is a funny exercise and I have only worked with a few managers and execs who could utilize it to their and the companies advantage. Most of the time the perception of low risk whether or not the alternative has a better payoff is the path most often taken.
can’t say about prayer odds but the hope odds is certainly more than 5%…
But still you need to work on ground and make strategies and implement them…