I actually wanted to post LPs on my channel, but I need to sort out my setup first.
And I'm also not confident in my ability to entertain, but hey, it's worth a try, right? :P
I don't think you need to play Armageddon to understand the original timeline. Armageddon was a fanservice game Midway made because they had financial difficulties and thought they could go under. After they made MK vs DC, however, they got a boost and reformed under Netherrealm Studios, and made MK and Injustice.
The games relevant to the original timeline IIRC are MK1 and 2, UMK3/MK Trilogy, MK Mythologies: Sub-Zero, MK Gold (which was a remastered MK4 exclusive to the Dreamcast), MK Deadly Alliance, MK Tournament Edition (GBA game, only important if you want to know Sektor's story and a bit of Sareena's as well), and MK Deception.