And I have a high level of skepticism that the percentage chance is accurate when I have a 73% chance (or more) to hit when aiming Ricochet at any of 4 targets and yet only one of them gets hit. What are the chances that three 73%+ chances to hit all miss? About 2 percent.
It might very well be that you have rolled those 2 percent of a chance to fail, and since the result is seeded that's what will always happen.
That's not a problem with the system, it's a problem with your expectations.
Welcome to XCOM.Errr... wrong game.