Human Irregulars are absolutly obsoleted by Scoundrels almost from the start as well. Their ranged is solid, but not amazing as well, and their melee avoid the high elf issue of being obscenely squishy.

Humans get access to an early healer in the Priest unit. I can't really suggest them, but they're by no means terrible. Orc, I've yet to really experiment with, but from what I have seen, they're an alright choice that doesn't really have a solid edge for Rogue. They're a solid choice if you don't mind squishy units, having a pretty even power curve all game long, and making backstab abuse easier. High Elf is great for general ranged combat, with storm sisters and archers both being standouts, but you're not going to take much else from them. Draconian flyers, however, are perhaps the best Racial T3's for rogues in the game. As such, Dwarf is a lacking choice, and Draconian is somewhat situational, having access to AoE being a double edged sword when your units are encircling the enemy. Their later units are universally melee, and their early units are only crossbow users at best. Rogue has an issue of having lackluster access to ranged options. The first thing when you're creating your character, is, as always, their Race and what magic you want to focus on.

Age of wonders 3 rogue specialization