[RayMarler]

Please note: I used Apiguard 15 years ago, maybe more, back when it first came out and got approved in California. I tried it one year and never again since. It may be that it's not the same thing now a days as it was way back then.

I've used both. I did not like the results of ApiGuard. It's strong and I did not like it's effects on the queen or the hive as a whole. No deaths, but it interrupts her laying, and the hive spends it's time trying to get rid of it or encase it. I didn't like the upset it caused in the hives and it didn't give me good results.
Apivar is great, the bees don't even act as if anything is there, including the queen, and it keeps the mites down for me. I've used it in the past and I'm using it now this is the 3rd year.

 

[RayMarler]

Ray
What schedule would you recommend when starting with new nucs in 10 frame deeps?

I can only tell you what I do here in my location.
I run all 8 frame medium boxes throughout, up to 3 boxes high.
In late March I put 2 apivar strips across the top bars of the bottom box.
This gives treatment during swarm season and drone brood production.
In September, I do the same thing again to give protection during fall population reduction and consolidation.
This has worked for me. 100% survival last 2 winters.
Other management factors ( and plain old dumb luck) may contribute to the success.

You starting off with nucs, I think I'd do an alcohol wash to see what loads are for now, and treat if needed, but for sure do the treatments in early fall after pulling off any honey you might get.