It sounds like the plants were used to shallow watering, especially if it was running every day in the winter. I would decrease the root depth to 12" to start. You even might want to increase the crop coefficient as high as 75% if the trees in the far background are yours too. It’s always a good idea to keep the setting for the wimpiest plants in mixed zones. Shrubs have shallower roots than trees and trees have a higher crop coefficient than shrubs. Eventually, you should be able to slowly increase the root depth over time. I would not go above an 18" root depth, even for established shrubs after 1-3 years of training the roots to grow deeper.
Do you know the flow rate nozzle inches/hr for sure? This will drastically affect the run times.
@azdavidr has a great calculator for flow rates. The link below is also helpful for the flow rate.
Drip Line Rate Calculator Insert the plant canopy dimensions instead of the distance between drip lines and emitter spacing in this link. Plants can also share water if they are close enough reducing the total amount of water needed.
Do you know if there are any leaks in your dripline? Those can also be major sources of wasted water.
This is the process of what I did when I got my Rachio 3 in December 2020. Setting Up Flex Daily in PHX with Mixed Plant Type