I was completely wrong, it's fairly hard to carry an entire team in this mode and you really need to wipe the enemy team to grab the flag and give it to a mobile character (although I capped as Zarya a bunch.
This mode requires more teamwork than normal competitive due to how close the enemy team spawns.
Winston is pretty great in this mode as everyone wants to play Symmetra, Ideally your defence and mid line also move up with you but still staggered to stop being back doored or also to kill enemy flag carriers on their way back.
Best event yet, beat Christmas and Halloween handily for me. The skins are better too.
I don't know why my game had to be patched for change Mei's waste line but whatever. I've been to Korea, it's really difficult to find a portly Korean woman. Ideally they would make Tracer 10 sizes larger lol.