Nah, ChaosGallantmon and the others do equate to Dark Digivolutions, but they're not all world enders. Megidramon is both a Dark Digivolution and a World End Scenario. Also MetalGreymon's Giga Blaster, and my extension whatever RizeGreymon's strongest gun attack is, are touted to be nuclear explosion equivalents. So either they're all not at that power, or they're all equally devastating. Either way, they're probably the same power, just not actual nukes.

Indeed. It's not like I'd have all that going on without a narrative reason and people being aware of it.