Covenant had some real problems. But it also gets undeserved hate.
Yes, apparently it's now cannon that David bio engineered some version of what we consider a xenomorph. There's some question still as to whether the one on LV-426 (that the crew of the Nostromo found) was one of his. it *looks* like one, but it's known that the adult xenomorph takes on some characteristics of the creature the face hugger attaches to. There are "doggo" xenomorphs and "person" xenomorphs in cannon. Assuming that the Nostromo found one of David's engineered xeno's however, he has 18 years from the end of Covenant to find, infect, and cause an Engineer to crash on LV-426. It can be reasonably assumed that since the Black Goo modifies the DNA of it's victims that whatever creature back on LV-223 that gave the Black Goo the blueprint for the face hugger lifecycle had some egg layer in it's cycle. Or David grabbed that trait from some creature native to the Covenant planet as he engineered the lifecycle to be robust during a lack of victims.
We now know that what looks like an alien skeleton from Alien, is in fact an Engineer flight suit so there's no need to think the wreck was, as Cpt. Dallas theorized, "thousands of years old".
As far as David's attack on the aliens, they are clearly not Engineers. They aren't albino, have different facial structure, and aren't a technological race. The only real tech on the uncharted planet is the Engineer's docking spire and it stands out starkly against the city it hovers over. It can be safely assumed that David wiped out another race the Engineer's seeded. FWIW, the city's reactions look a lot like an early race that comes out to see one of their "gods" ships come in, then get's plagued by surprise).
It does, as so many sci-fi horror stories do, rely on the idiocy of it's charecters to make the plot happen. It's not anything new or groundbreaking. It also requires a viewer to seek out and watch extra material from it's marketing on the internet to actually figure everything out. I don't like movies with homework. Especially James Franco centric homework.
