Yes, both components are rendered on the same outlet. I don’t know what causes the order of elements in that case? On my site it shows under the banner by default..
But you should be able to target the order with CSS declarations:
.below-site-header-outlet.categories-header {
order: -1 !important;
}
.below-site-header-outlet.banner-themes {
order: -2 !important ;
}