don't believe it would be any problem at all. I also feed my girls purina one. They enjoy it and I know it's not a great cat food but it is good and it has none of the nasty stuff that can cause problems for them. Maybe the best and easiest way to take them of the wet would be like a "12 step" thing. Not literally of course you get my meaning. Basically just wean them bit by bit and they should notice that they are getting less and less. I know that dry food is much better for them than the wet so it is probably a very good idea to do this.

Good Luck.