So if you watch the entire Leage (3 matches, 4 maps each) you'd get a minimum of 12 Tokens (Sometimes 15 if all three go to map 5) with three chances at getting 100 tokens.
Where you doing other things while watching? That messes it up sometimes. Twitch has some weird autodetect thing to make sure you are watching and don't have it tabbed away
they also said it can take a while until you get every token. i got 10 on the first day around 6hrs after the stream ended. today i logged on at the same time to find that i have 24... so i guess the 2 from yesterday came some time later...