So basically what I can gather is that Scrapper got a 5% crit chance against most mobs, 10% against leuts, and 15% against bosses.
They have a higher base dmg than brutes, but at about 75 Fury a brute hits harder (and lets be honest, getting high fury is not hard work), all the while a brute has better defense.
Also Stalker got a higher base dmg on their powersets, and a natural 10% crit chance against everything and crit on demand with assassin strike which hits like a truck - however, stalker got a bit more HP and defense overall than a stalker.
All in all a scrapper seems like a durable low dmg stalker while being a poor brute - whats the deal?