Like you say, a lot of what seems random is because you have to get used to the mechanics.It’s not that the game is random, but that it requires a different kind of playstyle compared to most other games. That is what it makes it special, though, so rather than make the beginning easier it would be better to have the start menu point starting players more clearly towards the scenarios. Those are actually closer to tutorials, rather than side-missions, as they help you get used to the combat under controlled circumstances. I noticed that this really helped me get into the game easier, as it made it obvious what I was doing wrong and how to improve on it. That’s harder to do when you keep getting thrown into different situations, while you don’t understand the basic mechanics yet. If you’re still having trouble, I’d recommend giving them a spin and seeing how you like them.
It might be helpful to know though that a deployment phase is planned, so that you can rearrange the position of your mercenaries at the start of combat, unless you get ambushed of course.
This thread and this thread also contain a lot of helpful tips that might help you get used to some of the more difficult aspects of the game. :)