I can merely share my personal experience with you. No way do i consider myself an expert on vasari, but i do play them and i do like them.
Obviously there is no winning strategy, as you always have to keep an eye on your enemies and adept to their every move.
Still here are a few key points i think deserve attention:
- Vasari get 2in1 resource techs, meaning that each level of the same tech boosts both crystal and mineral extraction. The techs also come on a very low tech level as well, so if you have 4 labs which you need for trade ports anyway, you can already put 4 levels into that research.
- You also get technologies that reduce the credit cost (L3 tech) and resource cost (L7 tech) of stuff you build. These are extremely important considering how expensive everything for you is in the beginning.
- You get a capital that has AoE phase jump prevention, the Evacuator. Use that... there is nothing better than to prevent the enemy from retreating and kill them to the last man, not to mention that the lvl6 special drain planet can quickly kill any planet with a health of 1500 or less, while giving some resources to you in the process.
- Gates.. nope, not Bill... Phase gates. L5 imperial tech (after the trade posts you only need one more lab to get them). If it is a single system map, then these gates can very well mean you victory. The enemy just can't backstab you anymore once you get these up on every planet as you can quickly move from one of your planets to the other regardless of actual phase lanes. Not to mention, that with this one being the first thing you build on newly conquered worlds, you can get home in an instant if the friends of the enemy you are hitting might decide to come after you. The capital ship with the phase stabilizer ability might help you as well, as it is a portable stabilizer node, allowing you to send reinforcements directly to that ship from any of your gate systems when the ability is active. Pretty neat eh?
- If that wouldnt be enough, there is the returning armada special. L8, but worth every thousand crystal you invest into getting it.
- Oh, i almost forgot.. research the missile branch of the tech tree fully once you got your imperial techs sorted.. Phasing is one of the big balancers of the vasari compared to the other races. It is the ability that makes your fleet of assailants stand a chance against the numerically superior fleets of other races. Also on L4 there is an upgrade for the assailant giving it splash (AoE) / increased damage.