I guess more to the point - how do gunlines fair in T9A?
Downtoned. Intentionally. because gunlines were felt to be unfun.
Both Dwarves, Empire, and all Elves can still build gunline style armies. IIRC Ogres might be able too, and maybe even O&G. Dwarves especially have high WS, T, and passable AS with access to the Shieldwall special rule, so their gunline troops can put up a resistance in close combat too.
I've let myself understand that the best working 'gunlines' in the 9th Age competitive meta are Dwarves with their warmachines and Sylvan Elves with their shooty avoidance skirmishing tactics. Of these two, Dwarves suffer from poor maneuverability, and in this age of chaff and MSU, are at a disadvantage against chaff/MSU tactics.
I think strong EoS gunlines would be similar to the Dwarven gunlines, i.e. EoS needs Artillery in order to really bring punch on the table. And no gunline is viable without some reliable CC units. But the present points categories sort of make it impossible to wield only shooters, so you will automatically pick at least some CC units.
-Z