You didn't understand the statement tbf.
Pure dps =3 specs, semi-hybird = 2 dps specs, true hybrid = 1 dps spec. (Arbitrary titles given by me)
If I understand correctly he wants the top dps specs to consist of at least one pure dps spec, while all hybrids can be found at least in the mid-tier. The bottom tier therefore is made up by specs whose dps counterpart already has a place in high/mid tier.