Personally, I don't allow pups in training access to unlimited water while crated; mostly because they just always make a mess with it. But I rarely leave them for more than four hours. If I had to leave them all day, I would definitely provide water. Your pups sound totally normal for their age. There will still be accidents for a long time to come. Particularly because they don't have an older dog to show them where the right place is to go. Your training would probably go more quickly if you limited the space they had while you are gone…it will be a long time before they realize it isn't appropriate to go in that big x-pen area, because they can "designate" one area the toilet, and another for sleeping, and another for eating, etc. That is why crate training works so well...they usually hate to potty where they sleep and eat. But, I can understand that you want them to have more space during the day...but just know it will take longer for house training
And, again, just my opinion, but I think pee-pee pads delay the whole idea 'the only place to potty is outside'. If you *want your dog to go potty on the pads regularly, then by all means use them (high rise apartment dwellers come to mind)..but if you want the dog to go outside, don't *give them a place to go inside...just clean up the accidents, and watch them all the time
I would imagine it will be more difficult to train littermates, because they kind of feed off each other. And it is hard to watch two ALL the time, because they go different directions Give yourself some time, and patience, and you will all do fine
By the way...looks like a really nice set up in the kitchen! Lucky pups.....