Disregard the above, it's not due to Hybrids, advanced or not. It's also not due to AI type, either, just tried with 'easy' ones on a few different seeds. It appears I'm either having bad luck or seeding of Mk III/IV worlds changed.
If you'd like an example of what I'm talking about, try seed 134173947 (Simple). Grab the Mirror world. You'll have a couple of Mk IV barrier worlds to your immediate right, another one trying to get into the south, and a chain of IIIs and IVs to your west.
But, again, this has nothing to do with Hybrids, sorry about chasing a Red Herring. I'm not used to seeing this many Mk III/IV worlds though, particularly in 7/7.