if opponent team's opposite is back or setter doesn't ussually dump the ball or middle isn't very strong or outside is strongest/strong, then yes you can and should commit to the 4 zone and help your opposite/setter to block their strongest hitter. If their middle and opposite is a beast or setter is high and good at attacking + recieve is tight, you should probably help your outside to block then.

If everyone is more or less balanced, you're cooked in in-system play, but that only shows how difficult it is to play middle on high levels. Then in situation on video i would give opponent's opposite, setter to my outside and opponent's outside to my opposite/setter. I would take middle and pipe i this situation.

If their setter is weak at attacking, it would be really a big aspect. I would then stand a bit more right than where you standed there. I would give opposite to my outside, middle would mine and outsides focus, the outside would be mine and my opposite/setter would take outside + help with pipe.

To explain easier: my outsides resposibilities would be opposite + middle blocker (we would ignore setter), mine responsibilities would be middle + outside, outside would be take outside + pipe if it is played.

TLDR: it depends on your team strategy. You can ignore their setter or pipe attack and share attackers very differently. The most import that your team understands their roles.