Dahlia planting depth question

I think I messed up with planting my dahlias. I've usually only grown a couple at a time, and only tried digging and saving once or twice, since I never had much luck. And, I never potted them up - just put directly in the garden. Last year I grew flowers for my daughter's wedding, and planted about 100 dahlias, so I decided to try to save them.

I had a pretty good return rate - almost too good! The spring was very cold, way too cold to plant, but the dahlias were sprouting in the basement. So I started potting them up, and also put many in flats with some potting soil. I had a limited amount of potting soil and thought I could get more tubers in the mix this way. And the ones in the pot were very shallowly planted.

They did great, but now when I'm going to plant them out, I realize all the growth is right at the tuber level. In other words, when you plant bare tubers, you put them a few inches below the soil level. But if I transplant these with the foliage at the same soil level as in the flats and pots, the tubers are barely a half inch below the soil.

Is this okay? Should I bury some of the foliage? Or will that damage the plant?

I had let them grow longer in the pots because they were more protected from slugs. Most of the foliage is anywhere from about 1 to 4 inches tall, and I've been planting them out with the larger foliage to again, protect from slugs. I guess I should have planted out earlier or planted more deeply to begin with.

I have many that are still just in the eye stage and I'm trying to plant those now, at the proper level. Of course now with those I have to worry about slugs. Always something, I guess.

My goodness, I could go into the dahlia business I have so many....