I'd estimate my success rate is higher, probably due to uni research, but it's enough to make me want to quit. I have finished motezuma now so I get 2 NTG's every time I get any and when I get with 5 star I get 4 but still, this is the worst part of the game . Why make something feel so much like a chore? I have had many extended breaks from wars just because it feels like work, not fun. Just give us Trade goods every 5 star!