Overall it is a nice and balanced Eldar list.
In my experience, Hemlocks are not worth it, they need to get close to do damage and end up losing the Alaitoc -1 benefit. The Crimson Hunter Exarch does the same thing better and for less points, while being able to keep that -2 to hit much easier. The rule with fliers is: either bring 3-6 Crimson Hunters/Exarchs or don't bring any
I would also drop the Vyper, it is not survivable and has no punch to it, it also need to get within 12" to do any real damage.
While Rangers are great, having 4 units of troops is usually redundant in an Eldar army, especially when you have 2 units of jetbikes that help with scoring.
If you drop the Hemlock, Vyper and 1 Ranger unit you would have 322 points open, which I would spend on 3 Night Spinners (real MVP unit, ignoring
LOS is amazing +
2D6 S7 D2 shots is amazing) or on 9 Support Weapons with Shadowweavers (9D6 S6 shots that ignore
LOS is really epic, while each platform is as survivable as a Vyper). Hide these units in a ruin out of
LOS and enjoy the rage of your opponent, while you blow them away. Turn 3 onwards, I start moving these guys out to take objectives etc.
In my Eldar lists, I never leave home without either Night Spinners or Support Weapons that ignore
LOS. Usually I take both 3 Night Spinners and 9 Support Weapons, you can't hide from that stuff and they eat through anything, even an IK that has Doom + Jinx on it. For example, they can clear out all the Tau drones that your opponent brings in a single shooting phase, especially if you put the autarch there for rerolls of 1 to hit.
You can also go for a 10 man unit of Swooping Hawks, they are really good against T3 infantry that you see a lot these days and they are fast for scoring objectives.
You can also drop the spirit stones on the Fire Prisms, 2 of them should be out of
LOS at all times anyways, you should use the Link Fire stratagem every turn on all 3 of them to focus down priority targets. That gives you 30 more points to play with.
On the Windriders I would change the Shuriken Cannons to Scatter Lasers, more shots is better than the rending, especially if you are shooting at something with an invulnerable save or has Doom+Jinx on it. You should be using Guide on these guys every turn. Be sure to use Fire and Fade on them too, to hide them after they shoot or to get to an objective they could not reach.
