The other faction is going to be called UIN thats a short for United Interstellar Nations. This faction is based on current EU plus some nearby countries.
UIN are quite advanced and are the only faction that uses massdriver technology. In addition they will have powerful particle beams and cannons that deal kinetic damage. Anti-armor section will include standard ballistic cannons (2 pdr, 6 pdr, 60 pdr) and powerful missile ordnance. They will get the most variable pd weapons ranging from Vickers Space Guns (analogue to RSF 14mm defence gun) and Bofors defence guns to powerful FLAKs.
Ships will be designed with a heavy focus on broadside engagements. All except for frigates that will mostly come with small weapons. All fighters will carry at least one missile-base small weapon. Hulls are going to be named after countries that formed this alliance.
Diplomatic status of the factions:
UIN and ISA are allies, they provide each other with ships and weapons (so an ISA cruiser with massdrivers or UIN coloured will be a common site)
XLE is neutral to UIN.
XLE and RSF are allies. They will interchange only weapons.
UIN is neutral to RSF.
ISA and RSF are in a cold war status (meaning that there is no global open warfare, but small local battles, raids, ambushes in ISA or RSF controlled space or in neutral territory are quite common).
EACH faction will have 40 weapons (except Aliens that will remain with their few weps they have now) with different properties and at least 1 ship in each class (except for pirates who wont have a cap ship). This will bring the mod to 160+ weapons.