A Battlebarge is much larger than cruisers,heawy cruisers and line ships.
Just read some lore books/web pages.
Are you talking about pre-heresy battle-barges? Because, sometimes, Astartes capital ships were simply called battle barges (regardless if they'd be better be designated as battleships) pre-heresy. You can read that on page 15 of forge world book Extermination
The Ultramarine battle barges (post-heresy) were outclassed by "vast degrees" by the Night Lord Legion's primary capital ships.
One of the Night Lords dispargingly insults the Codex Astartes. From the book Voidstalker
"‘The Codex Astartes in action,’ Ruven smirked. ‘Surrendering their largest and finest warships to the
newborn Imperial Navy. I pray that today the Thirteenth learn a lesson in whoring away their most
potent firepower to lesser men.’
Also the fact the Codex Astartes established a clear break between Space Marine space superiority and the Imperial Navy. Sorta silly to have that and allow Space Marines to maintain massive vessels as a rule of thumb. Some of the Chapters have gotten their hands on battleship-class vessels, but this is the exception and not the rule.
It's the same reason why Imperial Admirals have their panties in a bunch about the Nova
class frigates the Astartes run around with.
But if you are talking about post-heresy battle barges, I'd love to see them described as larger other line ships.