I think a better extended Guardian mission would have went like this...
1) The engineer gives 3 possible places to start, like now.
2) Go to the site, and find that site's "Rosetta stone" object.
3) With that one object in your SRV's hold, scan everything there that is scan-able. (While blasting panels, getting materials, and dealing with drones.)
4) Once everything there has been scanned, the player ends up with one complete piece of Guardian data, for turn in to the engineer.
5) Upon return and turn in, you may get something, but the engineer also says, 'based on this new data you provided, we need to look in this system'. A-ha! The next piece of the puzzle. Repeat 2-5 for that system.
6) You work your way to the end of the chain.
You've got space travel discovery, you got scanning, you got collection, you likely have some battling, with drones and some ships [of increasing difficulty, maybe]. It could have had everything. I think what they did, is an opportunity wasted. Sure you've got some repetition, but it's in a better place and keeps you moving through the galaxy.