I'm thinking if i slash weight these, it might be able to kill heavy gunners with viral and slash like the [Aksomati Prime] does

Tested:
It still deals the same amount of damage, but still grants a decent amount of slash procs to make a damage instance that bypasses armor... It will usually take an half [Mag] unless headshotting to kill those heavy grineer

If you want a [Twin Grakatas] build that uses viral but that doesnt suck your ammo most of the time... This is technically your build...
I still say corrosive works better on these