In general, what are the nuances when playing as Barbarian, say, with a random hero?"
Of course, yes. Take a look yourself, 30+ wolves on level 111, a very strong second skill.
As for the other heroes, Dessu has been nerfed, as have all the logistics heroes. The slow effect has been removed from Gundula's spellbook. Jaber and Grechkin are quite strong - they have been buffed. Gurnisson has also returned to his former self; he has been slightly improved, as artillery gives orcs +15% damage. Kragg has a lower chance of getting bad luck, as he only has the basic offense skill - that's how it is.
And Shiva is strong, especially with a hidden ability.