Regarding the B4:
Why not give it less AoE, but strong suppression?
It would "explain" the huge explosion and give visually satisfying feedback without forcing huge AoE damage to achieve this effect (a big explosion with little AoE will break immersion. Suppression effects might this discrepancy). It would also ensure that it will be used as a support weapon, since the suppression will quickly wear off if combat is not started immediately.
Suddenly it has something that sets it apart from the howitzer and can still win a fight decisively.
Oh why not nerf the killing power it has to add a bit of suppression... no bro no thanks. why not add suppression and keep the little killing power it has