That's true, often teams competing in the European League show different performances or vice versa, because basically they don't only target winning trophies, but tickets to the Champions League too. Sometimes competition in the domestic league is very tight, so they have difficulty finishing in the top four of the standings, so they will shift their main focus to the European League to be able to get tickets to the Champions League. Statistically, the reputation of Liverpool and Leverkusen this season is quite impressive, both have stable performance, so they deserve to be favored over other contestants.
In the European League, it will actually be even more difficult for small and weak teams to get tickets to the Champions League because here only one candidate will get a ticket to the Champions League. That is, the candidate who can win, while the others will not get anything and what we see now is that Liverpool and Leverkusen are both strong teams in their respective domestic leagues and even if they can't win the European League, both teams are already has the opportunity to get a ticket to the Champions League through its own domestic League.