In fairness though, when the vast majority of Order's armies follow Sigmar, a god who has thus far been nothing but benevolent and the rest of the Alliances have malevolent aims (corrupt everything, kill everything, kill-then-undeath everything) it's not difficult at all to see why people call Order the good guys. Groups like the Daughters of Khaine are more like the Token Evil Teammate. With the exception of them and the Darkling Covens, by and large Order is a pretty stellar bunch.
It's part of the reason I detest Nagash being written as having ran around getting rid of every other Underworld/Death God. It just turned Death into yet another "we kill because our leader(s) a ******" when there could have been a lot of potential for a much more nuanced alternative to Order, where Death isn't necessarily something to be feared, gods who give a damn about protecting the souls of their charges, etc. We see hints of this in the fiction, but it all falls flat when Nagash is just such an unrepentant arsehole backed up by his harem of arsehole lieutenants. I really hope we see more Death Gods appear that he can't just nom... somebody akin to what Morr was, albeit not on Sigmar's payroll (or dead-dead).