I think I would tatoo a 1,2,3, &4 on their foreheads, and that would also be their names. Like the Dr Suess characters with A and B on their shirts.
We have 3 girls born within 2y4m from 1st to 3rd, and have learned to color code everything. One daughter is pink, one blue, and one orange (they picked thier fav colors themselves). So towels, cups, plates, and other odds and ends belong to each based on color.
And who is going to move into a house with all those kids and babies for one year, I wouldn't bother, just hunker down and get them grown some first.