BR 1 Bolt Action with Light Tank/Plane WW2 Early War
BR 2 BR 2 gear Semi action rifle with Bolt Action with some Medium/Light Tank/Plane WW2 Mid War.
BR 3 Serious Semi action rifle with Medium Tank/Plane action WW2 Mid War.
BR 4 I am Speed sometime(Jet and other stuff)
BR 5 What is WW2?? (supersonic everything)
Just make all BR to +0 as a separate entity.