Easiest:
TL - DRG - T1 - MIBR
TL - RRQ - EDG - MIBR
Liquid favored:
TL - NRG - T1 - XLG
TL - RRQ - SEN - XLG
Hardest:
TL - NRG - EDG - DRX
TL - DRG - SEN - DRX
any group with groupRX will be scary, although liquid are still favored to go 2-0 in any of these groups