The Conqueror, an Imperial Star Destroyer, is armed with a planet-destroying weapon like the one on the Death Star battlestation.
"The Conqueror will destroy the Rebel Alliance, planet by planet!"
Now about the feat of destroying a planetoid. Firstly, this does not necessarily represent the full power of the Conqueror, as even the prototype Death Star can adjust its firepower
"I suggest we fire at only half strength, Director," Doxin said, scanning the technical readouts. His bald scalp furrowed again. "Even at reduced power the Death Star superlaser will be more than adequate to destroy a simple battleship. In that way we can manage multiple firings without depleting our reservoir so quickly. We won't have to wait so long between shots."
The Death Star itself also does this on two occasions, the first is when the Death Star attacks Jedha. In this instance, Tarkin ordered a single reactor ignition so the planet would not be destroyed. The second was on Scarif.
Lastly, the Imperial Commander's Guide places the small moon feat on a similar, if not lesser level than cracking a continent in half. Also, destroying a moon with a diameter of 200 km only reaches into the Country level range
Scaling the Eclipse to the Conqueror seems dubious, as it's neither weapon has been compared in any capacity. I doubt anyone would compare the two, since their storylines were written almost 17 years apart and the Eclipse never actually fires its weapon outside of games. Also, most guides agree that the Eclipse is weaker than the original Death Star.
According to many guides the Eclipse is 2/3rds as powerful as the Death Star. Many find this dubious, as do I, since the quote also says it can only "crack" a planet's crust, however, there's supporting evidence for the latter statement.
According to the The New Essential Guide to Vehicles and Vessels, the Eclipse can crack the crust of a planet. Although it also says just penetrating a planet's crust makes it "nearly as powerful as the Death Star."