The problem with that is, you're actually giving a pretty good description of the Mankhat.
It already does all of those things, and has all of those things. 10AD of heavy bolter in each arc, for a start- the baseline is very high. This ship has to be better, enough so to if not exactly justify then at least make not unfeasible it's cost.
The Superdreadnought follows the same naming scheme, but- side trip back to the 20th Century; PZkpfW VI 'Tiger'. Heavy tank- also, to a large extent, a blind alley, piling on more and more metal until it had the speed of a maimed snail. PZkpfW IV, Sherman, T-34 et al, medium tanks, lighter, differently built, and in time evolved into things like the Leopard-2A5. Wehrmacht vs. Bundeswehr would be a intriguing if very brief fight, and I for one would not be betting on the swastika boys.
The point is the Dilgar already have what amount to two separate basic lines of ship evolution, assault ships and strike cruisers, and the dreadnoughts are an interbreeding of the two. The genealogy of that works better than the chronology, that I have to admit.
The Tuvathrakur is a hybrid whose dominant side is the strike cruiser half, unsurprisingly when I say my usually deployed fleet consists almost exclusively of strike cruisers. The drivers- technically, the SHBs may qualify; their design ancestry is exactly that. Simply put, an MDC sabot firing a conventional bolter round. I suggested that as an alternative fire mode for drivers anyway- it's on page 1 of the thread, and it is a suggestion. There is an earlier, weaker version of them there somewhere, but the SDN's superheavies are the second generation, redesigned specifically for the job.
Many experiences with jammy Targrath have gone a long way to convince me there is nothing too big to be blown up. The Victory actually bought it on the third turn, after losing bridge, engines and damage control on the second; it wasn't quite that easy. One superheavy shot did split and produce 6-5 and 6-6 crits, admittedly.
The Carrier is skirmish, and the Ochlavita-C I'm starting to think is a fraction over- the quad pulsars being swapped out for pulsars seemed fair enough at the time, maybe it should be light pulsars, range 8.
Still to come are the two Wahant derivatives.