Nice report and welcome!
It does look like you made a (reasonably easy to make) rules error that I didn't see anyone catch:
Things started off quite badly for my Umenzi, with the Spearmen taking a rout check and failing. Since the backup unit was Shamans, who couldn't declare the "Back-up unit" rule, they ended up engaged and destroyed.
So, it was already noted that the Shamans could have backed up (though I'll personally add it might have been a bad idea anyway) but if your unit has a friend behind it, it can't end up engaged immediately after routing and get auto-killed. You basically assume there's a bit of "give" between friendly units, so the guys are at least allowed to leave combat.
Now, if the Dwarf turn was next they'd just final rush again and pick them up, but it does buy you a turn, and if your turn was next, you'd be able to rally them.
You might also be aware of this rule and just have meant that the Dwarves had the next turn, in which case, carry on.
Also, I agree 100% with Rush that Antonians and Chosen both rock the house.