The monsters are a lot nastier now, you do NOT want to leave cities undefended.
Ok, I don't leave my cities undefended--ever except in the beginning and then I build one as soon as I am able; but once I establish a perimeter I defend the borders strongly but the interior with lesser units(usually monsters do not spawn in controlled territory)--generally 1-2 depending where I am in the game. I noticed in 1.9 my city that was defended a peasant or observer would face a stronger unit. I just knew I was outmatched so I auto-resolved and hoped for the best. Turns out there was never a resolution. My unit & city survived.
I suppose I will find out but--- I am wondering if I might be attacked based on the quality and quantity of units present.
Yup--you have to, as my wife would say--"oh you mean defend-defend" You have the wrong combo of units in a city and a monster that spawns outside of your territory makes a fracking b-line toward your city--and you are potential toastI haven't lost one but I lost some decent units.....nice! game is more challenging.