The idea behind mercenaries is that they are cheaper in total resources, but you have to pursue a lot of metal to make them. They are also quickly trained and are more effective than their CS counterparts. So you just have to prioritize metal in your build if you want to use those units.

Hello @kheeva! Can you try the upcoming version of 0 A.D.? Test bundles are available at https://releases.wildfiregames.com/rc/ There are a few bugs that we are aware of, but let's check the sound on Tahoe with your help.  

BET

I figured out the instructions required setting the rally point before they were finished being recruited! ;P

Too late for a change in A28.