Two Kinds of Engineers. Two Species?

So I haven't seen, and possibly just haven't found anyone talking about yet, that there does seem to be two distinctly different species of engineers. In the beginning, we see one which appears to be seeding a planet with life. It's spacecraft more round, and dish shaped. His Body being very similar to human form.

Near the end of the movie, We see another, with more of a bio mechanical look to it, very similar to a Xeno from Aliens.

Some have theorized that it is a suit... but i'm not buying that. Look at that neck... seamless.

And completely different style ship, which goes along with the Bio-Mechanical style of the suit. 

Now reading about Alien Covenant, that there may be several species of humanoid creatures, like us, and engineers... This was probably our first glimpse at that. I'm so curious to find out more about these two drastically different kinds. And are there any more we have not seen?