I don't know how many answers you'll get on this board since it skews young, maybe also cross post at Bogleheads (if you haven't already). From my experience, those projected success %'ages were not all that common back in 2008 and I'd imagine they are pretty narrow since you don't have your entire financial life in each calculator nor do you probably update regularly. Many of them seem 'proprietary', so you have to read the disclaimers. I don't have a strong opinion on Vanguard's, but that would be pretty disappointing if you saw the success % change after a collapse and you could just disregard it. The numbers should be based on all of the available market history, including historical bear markets. If we get something 'off the charts', like a 75% collapse or 10 year bear market, then you'll probably be disregarding the success % number anyways!
IMHO, you'll probably have better luck sticking with FIRECalc and cFIREsim, updating projections using tax-caster software and social security estimator, keeping up with your state's ACA plans and costs, and doing the work yourself so that you can test scenarios and understand the limitations of the software.