Late war tanks and planes will probably have the highest br, way more than late war infantry weapons.
I dont think foeodorv or ppsh have higher br than is 1 or 2 . But most xp farm you can get is with infantry often
Step 1: Choose some very low level planes and tanks like I-IS3 M or T-26 before war
Step 2: Equip your all class 1 smg and lmg guys with high end weapons like rd 44, svt 40, feodorov, ppsh and give them tons of grenades pouches, tnts
Step 3: enjoy the xp farm and slaughter
Except you’ll get paired with other people doing the same, so it’s not abusive
Is this what, your 10th post roasting the new progression
You’ll probably be matched according to the highest level weapon you have.
According to @James_Grove , both weapons and vehicles will be taken into account by the matchmaker so you won’t be able to do this.
Since they already announced that it will TRY to match you with equal battle rating players and then work down, I think the only options are going to be to sandbag your gear really hard to keep out of high-tier, or to embrace high tier because you’re going to match with them anyway with mid to high gear.
The most of the alli players are 90% sniper. Objective play is not an option 
Greyzone tanking and flamethrower spam 
ohh sry I forgot the phosphor spam But winning is there not an option They can abuse so much they want. Skill Issues everywhere. The new system will be great.
I hoping on West / East / far East Front. Berlin for example is a mess. If we get the kiraly over all russian camps it will be sexy and delicious. No recoil PPSH and PPD bots can go lose then.