I say follow biass advice
T1 pd are delaying tools and unmicroed raid deniers
1 arty -> ded
If they try to stop your arty then your tanks will murder theirs at t1 as they try
Radar is very important as aeon. Have them far up , also consider more air presence (and therefore, air scouts ), as you don't need as much land due to aurora, put mass into air
If you don't see a raid coming, more intel with radars, land scouts, air scouts. If you do and can't stop it, better positioning of your army, or maybe just put up t1 pd to cover areas. Like said before, they're delaying tools.
Also, walls.
Raiding can mean a few different things, e.g a couple of units or a large number, in the first case if you're not able to pay attention to those units for a bit then yes it's harder with aurora, in the second large numbers of aurora should wipe out any other t1 force as long as you're not too heavily outnumbered, and if you have a larger force you should def pay more attention to it
Against t2 pd, there is mml in the game, and later t3 arty
skip t2 as much as possible with your t1 advantage and bring harbs to kill all