So on that analagy because its not governed by regulations its not important! What a load of tosh!
Im not saying everyone wears zip together its everyones own opinion but stating its not important is a massive statement that is just totally wrong!
Having whitnessed first hand a crash and a long slide on my back where the leather jacket rode up and wore the inside of the jacket and the zip holding the jacket and torusers together to the point where I had to cut the connecting zip as it was so badly worn that it wouldn't come undone I will always zip togather and I will always recommend to wear zip together clothing
But as clothing is not governed by regs its not important is it
To the OP buy what you want and be carefull of what advice you take as some of it is just peoples opinions! they aren't always right despite thinking they always are!
There is nothing wrong with having as much protection as you want. Its best to be well protected and not need it then not protected and need it
The type of crash will always dictaate the protection you need but every single crash is different