I think there may be some general tiers, but really this would be an impossible list/question to answer. Also, any template can be adjusted by choosing a lower/higher TM. However:
In general, using lower TM’s, 5’s PRO, and 5x5 FSL will be easier. For a beginner, this might be too easy but for a strong, experienced lifter this might be the sweet spot.
In general, higher TM’s, 531 with AMRAP on the final set, and 5x10 (BBB) or widowmaker (20+ reps at FSL) will be harder. These are great for younger lifters, weaker/beginners (if they at least have their form down), or for short term challenges for stronger/more experienced lifters.
Because assistance can be personalized, this can really change how hard a template is. Consider the two assistance choices below:
Option 1: 50 weighted pull ups, 50 weighted dips, 50 goblet squats with 85 lbs dumb bell.
Option 2: 50 DB curls, 50 push ups, and 50 sit ups.
Obviously Option 1 would make that a very challenging workout, and would likely require that person to adjust the main lift and supplement options. Option 2 would be much easier, and could be a good choice for someone really pushing their main/supplemental work.
This is really the beauty of 531. Once you get a hang of the principles, you can adjust programs, and even individual workouts, to suite your level and your current goals. Also, there are “challenges” that are more prescriptive in the exact TM, assistance, etc… that tend to be, well, challenging. I just did Building the Monolith, with had me doing 100 pull ups and 100 dips (in addition to tough barbell work). This would not be doable for everyone, and I’d say in general the challenges would be better suited for someone with a reasonable strength level.
Plenty of others on the forum have lots of experience and knowledge about running 531, and they may have more to add (or different opinions entirely).