The NFL has a strength of schedule formula that's simple to understand. Just take the opponents' records from the previous season, add up the wins and losses and calculate a percentage for all 17 opponents. In fantasy football, there's a different method. Rather than using team records, we use the number of PPR points allowed by defenses against a single position the previous season and rank the teams/players according to the average.
The numbers, admittedly, can be very close in many cases.
For example, the most favorable quarterback total (17.9) for this season is just 2.3 points more than the worst total. The tight end spot is even closer, as the best and worst slates are separated by 1.5 points. That’s why you shouldn’t use this data as a determining factor in whether you should draft a player. Instead, this is useful in picking between players with similar value in drafts.