It's a little early to be writing them off...but I agree they don't look impressive.
The Tigers on the other hand are giving me a really good feeling. Last year was fun, but there was luck involved. This year, there is no luck about it so far. They are just playing great ball. Their hitting will likely slow down, but their pitching should get better.
For what it's worth, I was just looking at their playoff odds on fangraphs and B-ref and they have the highest probability of any team in the American League.