t2 antiair (t2 sera ship as well) is direct counter to t2 air (usually)
t1 arty > t1 pd
t2 missile launcher > t2 pd
Rhino > auroras
t2 pd > t1 tanks
t2 pd + t1 pds > t2 tanks
Mercie > rambo
wall + medusa > t1 t2 land (except maybe range bots)
t2 pds are kinda only good way to stop gun acu
t1 aa is not great counter against t2 air (esp cyb vs cyb)
lab > artys (not work against way too much sera/cyb artys)
interceptor > gunship
gunships > t1 aa (or any no splash aa) cause they will avoid it until get critical mass
ASF > air exp
Aeon strats > land exp
cyb strats > bunched up armies
soul ripper + micro > all land except t3 SAM (t2 mobile flack have low range, and ripper kite them and kill one by one, if they try to be all in one place to shoot all together, they die to splash)
hoplites only thing that can be good against sera t2 bots (esp since medusa nerf)
snoop > mole
cyb aeon destroyers > subs (esp in real game and after t3 sub nerf)
cruiser in naval army helps against t2 stealth subs, cause it have significant vision range