@AzJazz You are me, just with a different screen name. Same area of Phx, I have 1300 sq ft on 3 zones… you’ll get thru this, trust me 
First, if you hand raked the thatch, you probably didn’t get it nearly as well as a machine can get it. Plus 1100 sq ft is a lot for manual dethatching. @azdavidr and I already discussed how backbreaking just doing his smaller lawn is. I guarantee you that your issue is a watering issue, just like mine… check out my post if you haven’t yet…
Do this like I did if you haven’t already
Soil: Sandy Loam (AW is 0.12)
Root depth: go to 6" since you do not have strong roots in those areas.
Allowed depletion: keep at default 50
Effeciency: if defaults to 90, but if you have clogged/broken heads, I guarantee you that your effeciency is much lower… probably sub 50. A catch cup test will do this for you. You can check out the store, but I bought the orbits on amazon FYI, love that one because it does all the calculations on line Watering strategies to fix this bad area - #26 by Modawg2k
Crop Coeffeicient: Default is 0.65… but i was running 0.73 all summer because of an older default setting in Rachio
Sun: just mark it for lots of sun.
Visually inspect your heads, it’s easy to see if you there is a gap in yoour spray arc… get cheap orbi replacement heads at Lowes