Preliminary placement with the Italian Greyhound says this will work!
I will have to train the Russell's to sit in the bags, but that should not be too tough. I would take a picture of them in the racks, but it's too early in the morning and too cold to get them up and out of their warm beds in their crates in the laundry room. The Italian Greyhound is actually a bit taller, if a tiny bit lighter.
It's also too cold to fix the bags to the bike right now. Besides, rack-training for the dogs should occur on a nice stable floor. I will cut down an old rug for a solid paw-comfortable bottom for the bag. A clip from the collar to the bottom of the bag will prevent the dogs from jumping out. Might be perfect; we shall see!