little to none
The ore freighter was a Scarran vessel used to transport and possibly aid in harvesting raw materials. The vessels were likely unarmed.
When the crew of Moya installed a sensor distorter on the Leviathan, they were able to mimic an ore freighter enough to convince a nearby dreadnought.
- The fact that Sikozu was able to convince the dreadnought that a freighter's crew would fear being boarded by an unarmed Leviathan indicates very light or no armament.