Hello,
Incase, if you don't have 2 seperate groups for 32 bit and 64 bit, then you would have to add both packages in order for both 32 / 64 machines to get the right install.
In other words, You can assign a 32-bit and 64-bit package to the same group when you do an auto-upgrade and both clients will automatically upgrade. You don't have to create separate groups for 32-bit and 64-bit clients
Nothing to worry.
Hope that helps!!