General Use for Grineer/Corrupted/Corpus:
Viral Damage is because when you fully armor strip enemies in one cast, grineer/corrupted cloned flesh health takes 75% bonus damage to Viral. Any bonus viral procs further increase damage to health.

Electric damage has a bonus against certain enemies like murmur, corpus machinery and is boosted by the Primed electric mod.

If you don't full strip with Pillage (which is unusual since just spamming pillage will eventually full strip), you could run Corrosive + Heat instead, which is also very good against unstripped acolytes, thrax and deimos infested.

For Crit Balefire: Run Arcane Avenger for flat 45% crit chance boost and swap [Lethal Torrent] for [Primed Target Cracker]. Do NOT use any Crit Chance mods as the bonus will be extremely low due to the low base crit chance.