I feel that my race of choice may be slightly detouring to play as a beginner, so i've decided to show how i play them. With most races i can compete with genius level AI in a 2v1 at war almost the entire game, so i would consider myself an above average player, though i will admit i have not put much time into GC3 since purchasing it almost a year ago.
The very first concern of mine is to ensure that my population's production is focused solely on infrastructure production and research. I do this by adjusting the Production Spending Palette(PSP) to focus entirely on Research and Manufacturing. The Research/Manufacturing Ratio is entirely up to personal preference, as you can see i have a significant emphasis on Research. Below the PSP, you will see a slider. This slider controls the % of manufacturing production that will be allocated to the Social and Military Manufacturing sub-groups. Given that my shipyard will not be producing anything soon, i adjust the slider to 100% social and speed up the planet's infrastructure construction rate. The purpose of these settings is to ensure that my research rate outpaces my infrastructure slightly in order to keep my planets busy upgrading the entire time. Since my first research goals will be to ensure that my "factories" and research centers are to Mega/Omega tech availability first, my planets will be busy working all the way through to the Age of War, resulting in efficient usage of turns.
Next, I have to decide on the infrastructure for my planet/s. Out of preference, I try to use my homeworld as a manufacturing hub, but always remember that manufacturing is a local resource, while research is a global resource. Meaning, 20 slots worth of manufacturing spread out over 5 planets evenly (without adjacency modifiers) is 99% of the time, significantly less efficient than the same amount of slots, over the same amount of planets, but put into research upgrades. So, to clear that up a bit, a manufacturing-specialized planet is the most efficient manufacturing method currently. I then use my tertiary planet (which i colonize on turn 1) as a research, influence and economic planet. In the beginning, Drengins do not have access to farms or markets, etc. Therefor, research takes the majority of planet slots from the tertiary planet. Be sure to RUSH your factories for the first 3 or 4 turns. I highly recommend researching Planetary Exploration in order to build farms and Hospitals. A hospital should be on every planet before it reaches population cap.
As i mentioned in the very beginning, my tech tree will focus heavily on infrastructure research. I want my planets to never be stagnant and for my infrastructure to be as efficient as possible to support my heavy military production the moment The Age of War tech tree becomes available. Once you have researched Slave Pits and Persuasive Research, you need to prepare for the age of war. Because the Drengins are warmongerers, to focus on planetary improvements, such as terraforming to increase planet class/slots would be counter-intuitive this early on. Our strength lies in our ability to meet the enemy head-on and open the path to their planets. In preparation for Age of War, follow the Militarization tech path all the way to War Machine. Researching War Machine during the Age of Expansion will set you up to begin research of Planetary Invasion IMMEDIATELY upon Age of War tech availability. Once you have completed War Machine, decide on the path you want to take for weapons and defenses, I recommend researching all defenses to their lowest tech-level in order to give your fleets more survivability. As for weapons, I generally rely on the nearest quantity of mining resources to dictate that path. There's no need to research weapons too far, because later on you will dump your production points into military production % and produce ships every turn. All you have to do, is open a path long enough to allow your transport ships to commence their invasions. It's quite easy to eliminate a nearby civilization in multiplayer and single player games within the first 15 moves of Age of War. This will provide you with 2-3 new planets very early and an enormous amount of increased influence within the UP.
If you would like me to go into greater detail on drengin war strategy or infrastructure, let me know guys. I hope this short guide helps my fellow drengin enthusiasts. If you have any other questions about Drengin or would like a guide/explanation for anything Drengin related, please let me know by private messaging me and I will do my best.
(this one was made with 1 hand, as my right arm is currently in a cast whichis why the guide is brief and somewhat vague on more advanced dieas/explanations)
By turn 57 I have completed research of my Core technologies: Slave Pits, Persuasive Research, Planetary Exploitation, War Machine.
I also have two fully upgraded Planets with Slave Pit and Hospitals on both. I now have 60% of the Age of Expansion left to research optimal techs. Quite obviously, I would want Weapons Systems and Defense Systems and then specialize within those tech trees. I could then research Medium Hulls and Life support or Ion Drive to give my ships longer range/move speed depending on whether or not it's needed for my planetary invasions.
This tech order and general Drengin Guide, should help you play drengin on a higher level and gives you freedom to build your planets and fleets with flexibility.