With damage 2.0, Corpus weapons deals mostly Puncture Damage wich deals more damage against armor targets, and Grineer ones deals mostly Impact Damage, dealing more damage to shielded enemies... even, either facton have weapons (Flux Rifle, Ignis) with does more damage to Infested...
As much as the Jackal using rockets and the like makes it seem like a grineer Bombard.
The Jackal Is Corpus.
This is why corpus containers (cylindars grey/green) are dropped from the ceiling
This is why you fight through crewmen and moas to get to it.
This is why there are Moa pods (potentially hackable) on the way to it
This is why the map tileset is corpus.
This is why the MineLayer drones can fly into the fight and drop a billion yellow energy orbs of explodiness while you hammer away at the jackal.
The Jackal is corpus.
Also. The -other- Jackal mentioned is not inactive. The One I found was moving/breathing-like
Grineer seem to like making taunts about Hanging your warframe on their wall/etc.. War trophy seems logical.
AS for corpus damage
from what I've seen, Corpus use mostly laser/beam related tech.
To which do radiation damage,
Radiation damage deals -high- "punch through" to alloy armor. Which Tenno (most or all)and some grineer are classified to have.
Grineer have mostly impact as stated, though. Aside from the Miter (slash with a fairly high proc chance it seems) and generally a large amount of what seems to cause slash/bleeding from a large number of their higher level units.
Grineer - Impact, heat, slash, blast. (high to low)
Theres this wonderous thing called lore mate, also, the "jakal" themed in Dark sector seems to be VERY old (Darksector being before the tenno) So the ORIGINAL jakal idea may very well have come from grineer, then salvaged and updated by the corpus.
The Corpus are Trader, as far i know, there are corpus who sell corpus tech to grinners and Tenno, so why not selling a modified jackal and keep a more advanced one (original jackal) to stay in the fight.