Tough spot in the game
@Henroo. I only have elven cities (so far). The Training Grounds and Mercenary Camp units are specialists that seem to do better once they are 2star. Cerebus is an outlier: early game, their range makes them superior, but you get to where it takes over twice as long to train them as sword dancers fairly quickly. Range is good, but not twice as good. Sorceress will never be as good as a Priest, but they can be useful. Banshees are good against heavy range at 2star; by the time they're 3star they're excellent against heavy range and decent against heavy melee.
I played my first city for over a year before I built the 2nd city. What I decided to do there, since I knew the value of the specialist troops later on, was to build training grounds and merc camp as soon as I could and upgrade them when I opened the techs. I spent a great deal of time not training those troops except to extend my training queue time for overnights, etc. I used the generalists trained in the Barracks for quite some time and Sorceresses did well in provinces where mages are the key unit. More issues with them when using them as support units. They outperformed the Blossom Mages when the Blossoms were 1star. Now that my Blossoms are 2star in my 2nd city, I rarely use Sorceresses. I do use a mix of Blossoms and Banshees at times. But by building and upgrading those buildings as I went, I didn't have to play 'catch-up' when I hit those fights where the specialist units were useful again. In Elementals now, and my training times are back to being outrageous in the Training Grounds, so I train Barracks and Merc Camp units now, again throwing in a couple Training Grounds units when I'm going to be afk.