Pwerfer can squad wipe with the single burst he got.
Calliope will wipe but not with the first salvo (unless you're unlucky), sure it will wipe with the 3 salvos.
Pwerfer counter by light vehicule ? If you let your Pwerfer being destroy AT YOUR BASE by a light vehicule, you deserv to loose it
Armor is worthless, perhaps you should learn insta counter like loiter and strafe that one shot sherman.
yes you do get people who will rush a cheap T70 or stuart into your base to one shot your pwerfer and retreat. Ostheer has many ways to defend against this including mines and ATGs and tanks if you have any, but light vehicles can still slip past your defenses and if they do, youve lost your pwerfer.
As soviets you can also call in partisan tank hunters from ambient building to quickly finish off both pwerfers and stukas.
In comparison, the calliopie will only be killed by an equivalently (nearly) expensive vehicle that requires you to first get to the vehicle, survive long enough to shoot 4 times at it (assuming they all hit) and hopefully be able to get out of their alive. I dont think i would say having to sacrifice an equally expensive unit to kill something would be considered a "counter".
Stuka loiter or strafe you need the right commander, LOS on your target, and the hope that your enemy isnt paying attention. Probably your best bet but if it fails, youve wasted your munitions.
If you are scared of your calliopie being killed by the 200 + 80 munitions loiter stuka + recon (which cant be called in your base) then simply hop out of your calliopie and laugh as they fly over you without firing at you (stuka loiter only targets vehicles now).
Yes armor is harder to deal with on mobile artillery.
Oh and the first salvo his vet 0 calliopie wiped 2 full health gren squads, the third finished the nearly out of range third gren squad.
As i mentioned, they were leaving my base (they were full health.