How were they not absolutely murdered immediately?

On the one hand, yes, battle is legitimately dangerous and fighting in the front is indeed much more likely to get you killed. On the other hand, it's not as fatal as you're expecting, mainly because combat doesn't quite work as Hollywood or Total War envision it. Here's a few previous posts for your attention, which focus specifically on how likely one is to die on the front line of a hoplite battle:

• u/Iphikrates and u/Rittermeister note how infantry combat went for the Greeks and the Medievals;
• Iphikrates also goes further into the 'pulse theory' of combat;
• so does u/Hergrim (with a bit more Iphikrates) in this post asking about rioters versus police.
• and more Hergrim on the dimensions of combat.

Any good book recommendations that go over Greek tactics

While there are many other notable scholars who can give you a good grounding, since this is AskHistorians, I'm going to recommend one of our own. Roel Konijnendijk's Classical Greek Tactics: A Cultural History has a proper and thorough look at Greek warfare as a function of culture, not just a decontextualised look at hOw HoPlItEs FoUgHt. I highly recommend it to your attention.

And as always, if anyone wishes to address themselves to the matter of Greek warfare, please don't let this post stop you!

Bonus: Hoplites, schmoplites.