However the way i use the b4 is different from the ml-20
i mainly use the b4 as a close-midrange 'shotgun' howi. Just camp vp's with it, wait for a blob to push in, or bomb overextended okw t4's. The b4 also excel's imo more on 1v1/2v2 mapsize then 3v3/4v4 because u don't need much range to cover the relativly smaller maps. So u will experience less scatter. If u shoot relativly close, while having vision and keep in mind that the b4 tends to overshoot (if it scatters out of the circle so u 'under aim' the target) u can get kinda reliable model kills or even wipes. Now if u add 2 or more b4's u can reduce the rng factor on this distance significantly. all u need is one or 2 shots and u won’t need more because after that the enemy would start dodging a barrage from like for example a lefh or ml20 anyway. B4 maybe RNG dependend, but it has a better fire rate then the ml20 i'd say. U make one shot and then 30 sec later uready again, ml20 will prob still be busy with its barrage+cooldown at that time..
The ml-20 on the other hand only has a slow longer duration baragge, with a ton of scatter that, IF u wont hit anything with like in 1-3 shots will be dodged at any range. The only advantage the ml20 has over the b4 imo is that it is nice to bombard bases and okw structures. (the latter can even be done to some extent with the b4 but rng will be rough on bigger maps). Sadly I feel that the scatter on the ml-20 is not good enough that u can be on par with the lefh and counter bomb it reliably. And how can a bit more damage per shot help if u cant hit a target

If the ml20 scatter can be reduced so that its a clear winner over the b4 at distance, i think it can have its place in the sovejet arty line up. OFC dont over do it like with all things