Following your logic JT is better now with less DPS but with an artillery ability becouse its not specialised AT. I'll suprise you: that was a huge nerf.
Surely, the barrage should not be free on su-76. But nerfing its range or penetration will go a long way in rendering the unit useless.
btw. JT has an ability that is pretty much what su-76 barrage is, just with cost, more range and better shells.
Its not better. In no way.
with 3-4 76s you can wipe a weapon team or alpha strike a blob. It is very reliable with numbers and experience, while the JT AI is a gimmick given to justify a nerf.
As many have said higher tier armour should have more of an impact against them. A small pen nerf with a marginal cost for the barrage would go a long way.