The pools are done by performance within your own region at tokyo/lcq
Fnatic+liquid 1st/2nd of emea teams at tokyo and are both pool 1 because of Fnatic winning the event. Fut was the third of the emea teams so they get pool 2. Giants/Navi 1st/2nd at lcq(4th/5th overall in emea) and get pool 3+4.
The other regions are more straightforward: EG 1st, NRG 2nd, Loud 3rd in terms of performance at tokyo so pools 1, 2, and 3. Kru, 4th overall by winning LCQ, so pool 4. Same deal with APAC. PRX, DRX, T1 are in pools 1, 2 and 3 respectively because of tokyo and Zeta are pool 4 because of winning LCQ.
You might not like it but it does make sense. There is no riot bias as you claimed.