They need a Rank 6, but not one that rewards more stuff than the current Rank 5.
They need a viable rank between the current Rank 4 and Rank 5 offerings.
+1, wholly agree. The progression between Rank 1 through 4 is definitely organic and logical. However, the jump from Rank 4 to Rank 5 is obtuse and seems out of place. There should be a Rank 6, but that respective rank would assume the benefits of the current Rank 5, and the "new" Rank 5 would sit nicely in or about 5000 points - to make the 10,000 points more commensurate with the gain between 4 and 5. Perhaps dull down some of the rank benefits, e.g. 50% bounties for Arissa, but maintain 50 cargo allotment for Rank 5 and increase adversely for Rank 6, e.g. 100 cargo allotment.
The other suggestion I had is that since now undermining and PP related CZ's have increased per kill; respectively, 10 per kill CZ and 30 per kill undermining, the threshold value for undermining and PP related CZs should increase relative to the point gain increase considering the transfer of cargo is still a 1 to 1. This way Undermining will not be as easily obtained by adverse campaigns to undermine; for example, if System A requires 5000 fortification goods and 12,000 undermining points, increase undermining points reasonably by 3-5 times (as 10x will essentially negate entirely the benefit of the allocation increase FD recenly implemented).