I played a match on MTG Arena where, to my surprise, effects got resolved in my favor. I had a Vorinclex, Monstrous Raider on the battlefield and my opponent cast Verdant Rejuvenation. They pulled a bunch of sagas and their own Vorinclex, Monstrous Raider. At the moment my expectation was each Vorinclex would cancel out and the sagas would come with 1 counter, but they came up with 0.
My understanding is that their Monstrous Raider and sagas entering the battlefield together shouldn't be an issue. Previously on the same match my own Verdant Rejuvenation pulled a Lotus Cobra and other creatures while I had Ashaya, Soul of the Wild, causing the Cobra's landfall to trigger for all creatures put together into play.
Now checking the rulings for Vorinclex I can see:
If two or more effects attempt to modify how many counters would be put onto a permanent you control, you choose the order to apply those effects, no matter who controls the sources of those effects.
But Arena doesn't prompt for the order to apply replacement effects, as they don't use the stack [Edit: incorrect, there's an option to order these effects]. Could this be a bug/limitation where Arena decided to apply my Vorinclex first, reducing saga counters to 0, followed my opponent's Vorinclex?