Deroceras are not funny. What I think that they do not like at all is the defense metabolites of the plant. They go for the new growth and varieties/weak plants that do not show a quick browning reaction where they are nibbled, which means that photosynthesis is not at peak to fuel phenolic defense. I have stopped those (I hope!!!) with dwarf quail in the greenhouse and better care for carabid beetles in the beds. It was only a season that they were getting out of control here, so I do not have so much experience with them as with the other species, but from literature I know that the pattern of secondary metabolites is a prime candidate to explain there preferences.

Also I have seen that mulch over winter/early spring is a factor to avoid with high Deroceras pressure.