The goal is to show they can't build characters with their mechanics and thus do not understand their mechanics, or mechanics in general. Proving they failed at balance is much simpler. Make an all caster team. Rejoice in all the buffs. Steamroll encounter after encounter effortlessly until you get bored and abandon the system. As this can and has been done by at least one person already there's no point in rehashing it other than to hit the talking points, such as +60 HP for Wizards and +40 HP for Clerics and Druids, still having plenty of save or lose spells, the things that counter you are nerfed... and meanwhile non casters get nerfed hard.
Alternately don't make an all caster party. Watch the non casters get slaughtered repeatedly, just like unoptimized 3.5 characters would, except without the possibility to make them stop sucking. Eventually either the DM will catch on and drop the game like a girl he found out likes donkeyshows a bit too much or the DM will start fudging every other roll just to "Make his campaign have less character deaths than a blind playthrough of I Wanna Be the Guy".
Oh and Pathfinder put a Revivify+ in their core rules. You don't do that unless you expect people to die early and often. Fine if you're running a hardmode campaign where encounters start at CR + 2 and go up from there. Not fine if you're assuming the normal, baseline campaign will kill people so fucking much they'd actually need in combat rezing. That means you need to fix your classes so people are actually at par with the baseline. Too much to ask of drunken monkeys, I know.