I am playing Tau as allies for my Eldar.
Eldar: 1 Farseer on jetbike, 2-3 Jetbike units, 2x DA Serpents, 2 Prisms
Tau: Iridium commander w/ 2x Missiles, Puretide& DC, 2 Broadsides w/ Marker drones, 2x 10 Fire Warriors
I also field 2 Crisis suits. With the Farseer in the list, I can easily 'twin-link' them. But I tend to 'twin-link' the Prisms and/or Fire Warriors.
So that has led me to think that Twin-Linking their Missile pods and adding Flamers would be a nice addition. They can stay near the Tau "ball" to lend Supporting fire, and don't have to rely on the Seer. They could also Deep Strike to flame a backfield unit. But is it worth losing the shots?