Stab adds about +30 range, so a German Greatsword outreaches a LHB righswing indeed. It doesn't outreach the Glaive though.
And talking about OP weapons, let's take a look at the different melee weapon classes:
1h: Steel Pick, Side Sword
2h: German Greatsword, Barmace, Long Iron Mace (these were confirmed to lose crushthrough next patch so don't really count anymore)
polearms: Long Hafted Blade, Long Hafted Spiked Mace, Long Hafted Knobbed Mace, Glaive, Great Long Axe (this was confirmed to get unbalanced next patch so doesn't really count anymore)
But yes, 2H are ridiculously OP, NERF THEM NOW !!!!!!!!!!!!11111111111
Edit: To make it clear I'm not saying the lolstab shouldn't be nerfed, as I said before just fix the spinstabbing so you can only use the stab from range, otherwise it bounces and you're stunned. But do it for all weapons, not just 2H.