Right... That helps alot!

First off, swap around so your doing the Z5 first, then follow with the Z2-Pro......
With the Z5 's swirl hiding ability etc, I'd do this first and let it do it's job masking any little marks / swirls etc not taken out by any swirl removal you've been doing. Then I would build up a few coats of the Z2-Pro. Zaino isn't generally hard to work with but, it is known that when the weather gets colder it's not quite as easy to buff.... Just make sure the coats are as thin as possible to aid with the curing...... A few coats will build up the shine and the protection. Theres no fillers or anything in the Z2-Pro (supposedly) like there is in the Z5 , so effectively you'll be locking in the fillers that the Z5 has left behind, and should start getting a great shine.

You haven't mentioned what Zymol wax you're using? If it's a proper tub of Zymol then thats fine, and should give you added gloss and depth. Once you've waxed on top of Zaino though, if you want to do further coats of Z5 and Z2-Pro, you'll need to strip the wax and start again.
If you're using the Zymol cleaner wax from Halfords, then I would stop using it..... The cleaners in this 'Cleaner Wax' will pretty much strip all the Zaino and leave just it's own shine behind. This product is also known for beiong a pain and being streaky, especially when the weathers a bit damp and cold.

Anyway, hope that helps!?! If you still wanted to go for a proper carnauba wax over the top of the Zaino, then I'd go with Poorboy's Nattys Blue Wax would give you some nice added gloss but, see how you go with what you have first rather than spending more money for the sake of it. (What kind of salesman am I???!!!)...

Cheers.
Alex