Since artillery is out, and given our new surplus of Starlance CIWB's, A Titan killer/Heavy Grav tank seems to be a good choice. Superheavy's tend to demand either Horrifying amounts of resources to answer, Or other superheavies. Whether its answering Ork Superheavy's or forcing Biel-tan to have a response when they attack us, it seems like a useful stick to have right now to back up our Faster elements and Infantry.
While I am not opposed to designing a Starlance armed superheavy tank initially I believe that we will need a Starblade armed superheavy tank in the future.
In the "Worlds of Note"
threadmark the Ork planet of Biggadakka is noted for pumping out tons of walkers including full blown Gargants. Gargants should be roughly comparable to Imperial Reaver battle-titans which themselves are several steps above your average superheavy tank.
To put it into perspective the immediate tier after knight titans and superheavy tanks is occupied by vehicles like Ork Stompas and Imperial Acastus knight titans, this is followed by
Scout Titan tier units like Imperial Warhound titans and Ork Supa-Stompas before we finally reach the the
Battle-Titan tier occupied by Ork Gargants and Imperial Reavers at the lower rung with things like the Imperial Warlord and Ork Great-Gargant in the upper rung.
Visualization said:
[Baneblade Equiv (we are here) / Knights / Wraithknight] -> [Stompas / Acastus Knights] -> [Warhound Scout Titan / Supa-Stompa / Revenant] -> [Gargant / Reaver / Phantom] ->
[Warlord / Great Gargant] -> [Emperor Titan / Mega Gargant]
A superheavy Starlance, which is essentially a Turbolaser on steroids should be an excellent option against other superheavy tanks and should remain solid against even Scout Titan weight combatants like Supa Stompa's but I suspect that they will start struggling against true Gargants since lore and tabletop wise Volcano cannons appear to be the preferred over Turbolasers against Battle-Titan level enemies.
To support this, Imperial titans Reaver and up all run at-least one Volcano cannon and any superheavy tank (Baneblade Shadowsword and Space Marine Falchion) armed with them is considered an anti-titan specialist.
The Starblade by comparison is capable of outright overkilling a Warhound Scout Titan
A Starblade is a modified Starlance designed to engage Titan scale combatants, sacrificing the majority of its refire speed for even greater power - a single shot from a Starblade can core a fresh Warhound Titan like a mere infantryman hit by a Lascannon.
This compares very favorably against the Volcano cannon which lore-wise is only capable of crippling a fresh Warhound. With that in mind and the fact that the Starblade doesn't completely sacrifice it's refire speed for this raw power this pretty much points to it being the ideal weapon if we are faced with Ork Stompas and Gargants.
While an argument can be made that since superheavy Starlances in general are around 3 times as powerful and fire 4-5 times faster than Turbolasers that it should be serviceable against battle-titans the fact that the Starblade being able to overkill a Warhound is a notable thing suggests that the Starlance is not so powerful as to be able to do the Volcano cannon's job.
Anyways, here are my proposed superheavy tank designs:
The Suncleaver is a dedicated titan killer while the Sunlance is a generalist that should be able to handle anything up to a scout titan.
Edit:
Messed up System Slot conversion to Weapon Slots math, for revised designs, see
this post
Since I already covered the use cases for Starlance vs Starblade I'm going to just include my reasoning for the secondary weapons based on my old Starcleave tank design:
Since I doubt Biel Tan is going to bring any superheavies the Fatesever cannons should be a solid option against the agile lighter vehicles that they have while still being effective against Ork vehicles.
The Starcarvers are intended to deal with swarms of lighter vehicles (which the Orks and Eldar both have) and should also be good against TEQs like meganobs which the Orks will have.
The Fatecaster Rifles are there to deal with Eldar HVTs that Biel Tan will likely bring and also any important looking Orks.
The Heavy Needlers and Needler Rifles are there to deal with massed attacks from Orks and should be able to fill an area with Wraithbone fire to counter holofields.
