You are showing us plants that don't work, but you are not showing us what you need plants to do. We can't see the space or imagine how the plants are supposed to shape it.

Google doesn't seem to know about P. 'Glacier,' but knows about P. gracilior. Could that be it? Either that or Japanese Ligustrum, IMO, are too large for the skinny strip you are planting. (I have a Jap. Ligustrum whose trunk diameter is between 30" and 36". And it doesn't seem to be close to death yet.) You need what is typically thought of as a SHRUB ... one that is capable of being made into a tree form. Would variegated Pittosporum work for you?

Actually, Podocarpus gracilior is often used as a narrow, tall privacy screen in Southwest gardens. But it takes a lot of consistent, frequent pruning to maintain the desired height and narrow profile. Are you prepared to commit to that?

Apologies for the typo, yes I obviously meant Gracilior.

As far as commitment to trimming - I have someone that comes in once every 1-2 months. If that's often enough, then I should be fine.

Also open to other tree suggestions. Would the Podocarpus macrophyllus be a better fit here? We really like the ficus but it has to go.

Forgot to mention that landscaped area you see pictured is 4 feet deep.

I live in south OC. If the spot gets a fair amount of sun, Metrosideros excelsus 'Gala' is one you might consider, if you don't mind variegation. I have a hedge (mixed with a similar species that is not generally sold here) that is not against a wall/freestanding, yet I have easily maintained it to 3' wide with minimal pruning maintenance. It was maintained at 6' height, but I have allowed it to grow taller to block the motion lights of the house across the street. Easy to grow, and pest free for me.

I'd do a trellis that goes the desired height above the wall and use Star Jasmine (Trachelospermum jasminoides) to cover the trellis. Your pavement there will stay cleaner than having a shrub hedge. Once-a-year clipping of the vine should be about it for maintenance and no worries about width coming out from the wall or root systems that will eventually push up the pavement.

Depending on any height regulations. You could take a fence section, turn it on its side and make a trellis for any sort of climbing rose or vine. I think these are 8 feet long and about $100 each at Home Depot or Lowes.

some Irvine HOAs do not allow trellis to project above the height of the block wall—check your landscape guidelines. We use podocarpus gracilior for privacy screen and like it. Trim only 2-3 times a year. There is a considerable amount of shedding of long needle like leaves though. remarkably pest and disease free in my experience. we keep to a depth of 2 ft and about 10 ft high with no problem. can take both sun and shade. you could also consider green tower boxwood which is supposed to grow tall and narrow (up to about 9 ft tall) but its slower growing.