In the GUI Editor, for tabs, you can click a new tab option, but if you want to move a tabs contents to one in the list, you have to copy all the contents from that tab to another and rename the tab, i feel you should be able to define the position of the tabs that appear in the menu without having to do this.

Essentially, the tab number in the list should not define the displayed position in the overall tab bar.

Tab 1 - Name: 3
Tab 2 - Name: 2
Tab 3 - Name: 1