We’ve become used to almost 4 years of tuning and balancing, so yeah, the first attempt at something new is going to feel off. What 1/3/2 does though is that it re-orients how players have to think about team fights.
General
More DPS = more flank opportunities, deathball is way harder now.
-When you’re ahead, hold major chokes and watch your back.
-When you’re behind, get your team into split flanks that force the enemy to divert attention multiple ways.
DPS
DPS have to do more than fight from the cover of their tank line. You have to be extra careful and aware of where you are positioned, AND you have to coordinate more with your tanks and supports to make sure they aren’t taking too much heat, ESPECIALLY when the enemy team goes dive. Want heals? Gotta keep them alive, there’s no longer a tank to do that job for you.
Support
Support became more difficult again because now you no longer have the safety of two tanks that can peel dive (part of why dive is getting a lot of love with 3 dps). Consider swapping off heroes like Ana and Baptiste if the enemy uses D.Va (matrix blocks projectile heals) or all dive heroes.
Tank
Tank also became more difficult since you no longer have a buddy around to help you while your cooldowns reset. Remember that tanks without shields get DEMOLISHED by Rein shatters. Be open to working around the enemy tank player’s hero choice. DPS is higher than before and you can single-handedly drain the healing resources of BOTH of your supports if you play in the open too much. The DPS inherit more of the “make space” job, so calling targets with your view of the front-line is even stronger now.
I hope this helps you in your games. I’ve been enjoying the 1/3/2 and think that with some work (and some map reworks) this flanker-oriented style will be very interesting to play and watch. More flanks = way more stress, but it goes both ways and good players will capitalize on what I’ve written above.
Edit: Punctuation