I think this works best when you have a good mix of dive and static in your team
Heroes like Genji/Mercy/Winston that will dive in and wreck havoc up top, as you, zen and soldier enjoy the free ride at the bottom.
As soon as i’m under the bridge i’ll assess where the enemy is as the next shield counts -
If they want to run behind and chase us, i’ll drop the shield on the payload behind me so I can turn towards the enemy shielded whilst the payload is still moving
If they drop down the otherside of the bridge to setup a new def, I’ll usually jump off payload, drop a shield and leap frog forward until we’ve made a couple kills, by this point I’ve probably already got ult so can use it to push for the 1st checkpoint.
The key is always killing their shield / rein. I know how to outplay an orissa 9/10 times so for rein it’s just getting the shield down and he’s an easy pick
I should point out there’s times when orisa certainly isn’t an optimal pick, but you can definitely make it work a lot if you can time your shield / grav and fortify well.