The focuses are great most of the time. But do require baby sitting and sometimes further interdiction is required when your needs for that city become more specific.
It really depends on whether you're going all or wide though.
Tall: you more often than not have more general citizen management going on in your cities, as the cities themselves exist to fulfill many rolls. Also they grow so often for much of the game it can be hazardous to fiddle with locks. Automated citizens can remain reasonably optimized to changing conditions. Often If I lock in a template for them, I'll forget to update upon gaining population or completing tile improvements, losing more efficiency than I gained by optimizing it myself. If you're really diligent you can generally push the city a little harder with your own tweaking though.
A hammer missing here, or an extra food there are a relatively minor things in a 20 pop city, also nothing is really going to waste when the city has to do everything.
Wide: typically each city will have a very specific purpose. As a result citizen roles and population cap are much more consistent. When playing wide games I generally have every citizen in almost every city locked into place, with avoid growth on just in case.