Could anyone please explain to me in detail what these all do? All I could ever find about this topic was an old forum post where someone explained that these premium special abilities combine two non-premium ones, and that the blocker supposedly doesn't even work?

I have quite a few questions regarding this. How does it work if I already have a defensive wall DC but then I add an interception specialist too? In theory interception specialist includes defensive wall, no? So does that double defensive wall's effect? Or won't I be able to pick interception specialist in the first place because the guy already has defensive wall?

It would be nice to also get a confirmation of what exact special abilities these premium ones combine, if it even works like that? And is blocker really not functional?