I think I understand the confusion.
There are several topics all rolled into a single post here. I will try to provide answers for each (per my understanding)
1st, the issue of server system certification: the single-socket Xeon ASUS P9X79 WS is not certified for use with vSMP Foundation.
2nd, indeed, if using a certified server system (see http://www.scalemp.com/spec) you would be able to plug a Xeon Phi into it, and use it in what we call “Fused Mode” (showed under the title “aggregation” in the graphics you posted). A single server board (certified), and a single Xeon Phi card, is all that would be needed in this case.
3rd, if you wanted to aggregated multiple phi cards from multiple systems (as shown under “Co-processor Add-on” in the image), you would need at least two nodes.
BTW: it is worth noting that the Xeon Phi cores are hyperthreaded, so you will see more than “60 cores”, in terms of the logical CPU count.