Since you have scratches to remove, the DACP will remove the Klasse. So, removing the Klasse on those area's won't be a concern. If you wish, you could use AIO after DACP. Then Zaino after AIO. If you don't want to use AIO, you can just DACP then wash, then Z. If you want the paint totally stripped before Z, the alcohol method works pretty good.
The choice is really yours. I just use AIO as more of a paint prep tool. For most of my cars, I don't need to polish often. That's where AIO comes in handy for me. It's fairly mild, and cleans well. Basically, it lets me start over with having to use abrasives that I don't need. It gets the paint nice and clean, and IMO does not contain much polymer so I've never had bonding issues. I didn't notice any change in looks with AIO under Z. Just an option to think about. :up