The thing with the Vickers is that it works as intended. It is supposed to be the anchor of a gunline. The ideal thing with a Vickers is to have it behind 2 or 3 Infantry Sections in green cover and KILL THE SHIT out of Germans. The Brits play like a World War One army, it's best people remember that. They win attacks through brute force and they hold ground through killing and causing manpower bleed, the brits don't flank, they don't close, and they don't dance around cover. They sit in cover and shoot the enemy to death with the MG staying in the rear as a line backer, The MG is not supposed to be at the front, if it's getting fraged by OKW you're placing them poorly. If you're getting OSTH Rifle nades try leaving your MG's out of cover, yes it's heresy, but if you have a good 3 sections with brens infront of it, then it will survive.
Mortar says hi.
Regarding OP, its far suppression is low IMO. It needs less accuracy but higher suppression at far. Rifle nades also need range reduction when suppressed which is an ancient issue.