The hiding has a certain order - some tabs will be hidden before others.

It just hides tabs in order, rightmost first. (I'm not sure how it behaves on RTL wikis – see T36587 – but it's still in order there.)

This is because hewiki asked for the VE edit tab to be secondary to the WE edit tab. On normally-configured wikis, VE's edit tab goes later.

O the awfulness, why on Earth do we still have this setting.

I'm going to try to remove it.

@Amire80 @Jdforrester-WMF maybe we can close this task and create a new task " Disable setting VE edit tab to be secondary to the WE edit tab." (if still relevant?)

In T113157#5807087, @Jdlrobson wrote:

@Amire80 @Jdforrester-WMF maybe we can close this task and create a new task " Disable setting VE edit tab to be secondary to the WE edit tab." (if still relevant?)

No? That'd be a significant community-facing change.

OK I guess I misunderstood T113157#1671851 ?

Am I right in understanding this is a VisualEditor issue not a Vector issue?

In T113157#5807168, @Jdlrobson wrote:

OK I guess I misunderstood T113157#1671851 ?

Am I right in understanding this is a VisualEditor issue not a Vector issue?

Well, it's an MW issue but only affecting VE until T28918: Provide clean interface to register content editing interfaces is fixed, yes.