SC HotS is $40 at Amazon if anyone's interested. http://www.amazon.com/gp/product/B00...ce-full-site=1
I've already explained this, they are wearing armour, the squid face is the Protheans without their armour, the bug looking ones are Protheans with their armour. (I.E. The Collectors.) [rtfm]
I should have been a bit clearer before. The Protheans became extinct 50,000 years ago, yes, but they were a highly advanced race who had been around for much longer. As i've also said before, if an author is writing a trilogy, they don't answer all questions and reveal all the secrets in the first two books, in fact they purposely pose new questions and introduce new and confusing information to keep the reader wondering, it's to make them want to read the next instalment, in literary terms it's called a hook.
So you are being premature with you're assumptions, we don't have the first idea how they are going to write this into the story and tie up the loose ends, so perhaps you'd be better off actually waiting to see how they handle it, before jumping to conclusions. Which is all you're doing now, if these things are still unanswered by the end of ME3, then you have an axe to grind, until then, you're just pissing in the wind.
I know you've only just learnt that word, but you're flogging it to death.