It's true that there are some times that you can't hit positionals. However, smart use of positioning resolves a lot of this. And using optimized strategies solved even more. Unfortunately, pugs are NOT optimized in the slightest. For example, you can actually land positionals while doing Pantokrator on a melee class. However, it requires almost completely redesigning the strategy.

On lasers, you can use true SW, W, N and NE positions for both sets of lasers, and swap out with a second group of players, instead of having all 8 players at different directions. If you MNK on the NE position, you can access the flank/rear line and land all positionals while simultaneously baiting your laser. The N position is less ideal, but still allows for rear positionals.

The missile section is more complicated, and there are a vast number of patterns that can be used to control where each player runs at any given time to bait their AoEs while more or less staying on position for positionals. I couldn't tell you exactly what system to use though. I can just tell you that as a healer, I start at the true E edge and slide-cast towards the center, allowing me a 50% chance at finishing my Stone IV cast, since only 4 AoEs spawn under random players. Being separated from the group gives me a 50% chance of not being targeted. If I'm not targeted, I get to finish my cast.