Indeed. Unfortunately if someone applied the tactic, he already got 1 lose because Leverkusen failed to win in the second match. How if Leverkusen never played at their best level again this season? It will be a disaster if someone tries to rely on the tactic. Even in another league (ex: Serie A), there is no big team playing consistently. AC Milan and AS Roma are 2 examples of big teams but performed very badly in the early season. I just can't imagine if someone bets in these teams for the whole season.

Don't bet on Leverkusen, bet on Manchester City, Real Madrid or Bayern Munich, I'm sure the winning chance is 70%-80% from all match. Never hope an one season wonder team can be consistent, they're similar like Napoli, in Serie A every teams are not consistent, but Inter is better among other top teams.
I'd say Manchester City is more promising, they're always consistent.
Leverkusen isn't bad after all, so I don't know why the sentiment against them, if they are that bad, I believe they would rather not qualify for the champions League, I know for city, Madrid and Bayern, they are big names who will not want to loose not on their first games so it will not be so bad an idea to let them be your pick as winner but also they may disappoint.
They may draw in some cases but I don't think any of this three can loose what I thinks is going to be the best is to predict they win or draw Leverkusen inclusive, any of them can literally have any of this results .