O wow, what lvl is your Super Pershing at ? Those stats are are quite considerable.
I had one with 12 hp left after around 9 hours long gathering I set up before going to bed.

The only Artillery class tanks worth of anything are 4/5*
I have a 4* Artillery and her active skill multiplies her range. If active she actually becomes a real artillery and can cover fire the frontline tanks from half a map away.
Otherwise the artillery tanks seem a bit weak when compared to Destroyers simply because they dont really have that much extra range (which one kinda expects from something called an Artillery) and dont bring pretty much anything else onto the table really (well they have passive splash damage but thats meh anyway with that range).