I actually played a list very similar to your opponent's in the game where the Brets absolutely wrecked me (game was 1500 though, and my Ushabti didn't have bows).
For Brets, I think that two lances is far too little to be able to pressure the opponent in any meaningful way, and 3-man darts of GK are too good not to be taken.
Btw I get what you're saying about list building, as I too refuse to play armies that don't look like, well, armies (which is why I was put off Sigmar for a long while btw), but yours definitely has room for improvement, possibly even within said parameters.
But yeah, I'd definitely say his list was a lot more optimized than yours. Add those spicy rolls and gak mission deployment to the mix, and I can see why it could've felt frustrating.