If by DPs you mean DPS, then no, you do lose single target DPS - HS is more rage-efficient and does more damage, HS also procs Bloodsurge and with high gear it is queued almost all the time so you lose all those Bloodsurge procs. You're saying HS's damage is not that much higher, but that's with Imp Cleave and without factoring rage efficiency and Bloodsurge.
This reminds me of a BDK DPS discussion where someone was arguing that Obli > DS because its normal hits are higher. You just have to factor everything when you theorize which is better - A or B. And then also you have to realize which of the factors actually matter, just like jendah said.
And if Slam is your lowest contributor, then there's something wrong with your prioritization. With T10 set bonus and HS being on-queue almost all the time, in addition to BT and WW already, Slam is up on almost every GCD window and becomes a noticeable chunk of your pie chart.