I realized that the reason why Overseer is so cool and fun and so well done is because of Dark Heresy. Both Corsairs and Kroot have pet units, including your Kroot companion. They needed this mechanics for DH. Overseer is either backported to RT or was made with DH in mind

Also, after playing on Unfair+ where I actually experienced some difficulty for some time and had nice exchanges of fire and duels, had to utilize map and chokepoints, rethink my strategy and restart battles I too realized something. Cool battles take some time to play and game is already reaaaaally long. The fact that you can alpha strike everything now makes playing it bearable, but if they fix the balance and then add those two more dlcs (or more) getting through RT will be a really daunting task.
Might be why Dark Heresy is supposed to be shorter as well. Maybe they are planning to make more dlcs for it so base game can't be this long again.