Did they expect a grind?

I’m questioning the motive behind making us kill an ungodly amount of Protheans for Spartan Ops. Just playing naturally seems to yield little results, and I’ve actually had to grind certain levels just to keep all of my commendations at reasonably close levels.
The Covenant seem to be far more forgivable, as they spawn in vehicles, in which the drivers are usually higher ranked Generals, Officers, or Ultras.
Though Protheans on the other hand don’t have the luxury of spawning with vehicles, which makes reaching quotas for the higher ranking ones a bit tougher. (Some of the most notable are Crawler Snipers and Knight Commanders, which usually will only spawn one or two per Prothean map! D:)

I suppose asking to change spawn rates is a little much, so I’ll just ask the community:
Am I missing something? Is there an easier way of doing this or are we really just doomed to grind?

(I’d appreciate it if this didnt get turned into a hate thread, 343 did a great job with Spartan Ops and the commendation system. [especially the unlocks associated with it.] )

The crawler snipes.
So little of them!