Maybe even form new factions altogether. Grunt-Innie separatists and Jackal pirates would be fun to fight against.

: It'd be great if they just removed them outright, but that's unlikely.

No. No matter how many times I see this, I don't think the person saying it has thought things through.

The formula of the Covenant is getting stale, but the individual ingredients still have potential. In any case, the only alternative I see is throwing the lot out and buying a box of Promethean Mix from Wal-mart. Trust me, that's something you don't want to make a meal out of.

: So... they need to nerf the Watcher

A redesign wouldn't hurt either.

: and make the Knight distinctions more
: prominent.

Same could be said for the Covenant. I couldn't tell the difference between one rank and the next, though I get the inkling that the yellow ones were slightly easier to gun down.

: I.e. Knight Commanders are an atrocity, they abuse their ability and their
: overpowered gun's radius so they don't even need to aim to hit you.

Ah, just like the Rocket Flood of old.
Only, more annoying.

: I.e. Knights are prone to spamming grenades with Catch on, it's ridiculous!

Hah! What you know as "Catch", I knew as "Easy mode". When the Catch skull is on, the Knights spam grenades, a thoroughly ineffective attack with a long throw animation that leaves them exposed.

: Crawlers are fine as they are, the only ones done right IMO.

While you are correct in that they're the only ones that aren't completely broken, they're still boring to fight, and don't particularly strike me as 'Forerunner'.