While you might end up being right, I think you need to forget about the SAC games as they mean nothing. First, this Folsom team is better than their previous 2 teams. Second, Kaiden Bennett wasn't the QB in 2016 when they lost and Daniyel Ngata and Elijhah Badger weren't in the mix either -- among many other players. They all played in the close game in 2017, but much of the team has changed and those stud skill players have all improved. It's a different team.
Besides, Folsom has faced teams since SAC with athletes and blew most of them up. Helix had athletes and a 4-5 star CB. Didn't matter at all. DLS has an elite defense and Folsom moved the ball fairly well considering. We all know the reasons they didn't score, but they still moved the ball against an elite defense and made some big plays. GHS doesn't have anything close to DLS's defense.
I'd love to see the Pacers shock the world, of course, but I think you are making far too much of the SAC games by thinking it translates or somehow foreshadows what's going to happen on FRI.
The key to slowing Folsom's offense is less about matching their athletes and more about getting pressure and collapsing the pocket. If a team can do both, even better. But DLS had success because they made Kaiden Bennett uncomfortable in the pocket and didn't allow him to make many plays with his legs. If Grant Union can't duplicate that, their athletes won't matter. The best DB's and LB'ers in the world get exposed when a viable QB has a clean pocket and plenty of time to sling it.