The term synergy comes from the ancient Greek word syn-ergos, meaning 'working together'
I am having a feeling of deja vu. Me thinks Old School Terminator had some things to say about this as well, but in regard to his Tyranids over at Dark Future Games.
So how do you use your units together to achieve greater results. It sounds simple, but it really is not. As any seasoned Eldar player knows, a vast majority of your units are really good at one thing. The problem is that you must make all these specialists work like a well oiled machine and not have the whole army fall apart when one unit is destroyed. This is why many player give up on Eldar. They just cannot make it work.
So how do you make it work? The first thing you must do is give your units a job and make them stick to the job. The dire avengers are going to hold the objective. The Dark reapers are going to support the Dire Avengers by eliminating threats and approaching units. Giving a unit a job is basically tasking them with the one thing they are good at. If you re-task a unit every turn you loose efficiency and you potentially throw off the flow of the army. By re task I mean using the unit in a different capacity. Going from anti infantry to anti vehicle with dark reapers and not really supporting another unit. Fire Discipline must be maintained. You must resist the temptation to throw everything you have at one target. If you sacrifice support fire to take down a target that is not an immediate threat you risk loosing a n important unit or a unit holding an objective.
One of the most important forms of support is how you use your Seer Council or Farseer. As psychic powers are one major advantage the Eldar army has, you need to use them effectively and efficiently.
I Ideally like to have 2 Farseers. I use Eldrad Ulthran a lot as he is the best psyker in the game and he is a bargain at 210 points. This allows me to run an inexpensive second Farseer. Mobility is important for the second seer. I usually give the second seer only 2 powers and mount him on a jet bike. Fortune and Doom are your best power options. If there are lots of low leadership models I also give him Mind War. Mind war is an excellent way to deal with heavy weapons squads and specialists. You can remove specific models to assist your other units.
So basically to sum up you must stay on task and keep your eye on the prize so to speak. You will run into instances where a unit will get into a situation it is not equipped to deal with but this is why you must make sure you can support that unit with another that is good at that particular situation. Your opponet may strike at opportunity targets or just fire at the big shiny units they deem a threat. You must keep one thing in mind. If the game is objective based you must make the entire task and mission of the army as a whole to take and defend the objectives. If its a kill point mission then you must systematically eliminate each enemy unit one at a time.
Well there is my two cents. It may not be exact and may even be vague but that's what happens when you play Eldar. You have to essentially learn the army. They are not forgiving and easy to play like marines. Next time I am going to talk about how to approach different army types, IE shooty armies, deep striking armies and so on and so fourth.
Blood Runs, Anger Rises, Death Wakes, War Calls!!!!!!!!!!!!!!!!!!