Inferno cannons etc are generally accepted to be allowed for use on most capital ships. Bretonian, Kusari etc.
May not make much sense but getting rid of them from some factions would cause a lot of complaining about balance. Logic wise however, Liberty and the other houses ought to have their own specialised weaponry. Unfortunately they have nothing currently, so they need to use weapons such as the Inferno.
The big battlecruisers and battleships have nothing to do with the use of foreign weapons, merely how much people in Liberty like their capital ships.
