All classes can solo on WR. I solo'd Janseth(monk) to level 20 in 3 days before I started Anadin, with no twinking, and barely any buffs.
I didn't really solo much after that, as I started a shaman to go with him.
I will tell you that he can solo easily in Eldenals, and mielech. But that doesn't help you much, as he is also raid equipped and already has ~60AA.
Necros can solo very effectively, any mob that doesn't summon. Aggro kiting, and using pet as DPS works very well. If you can find a rogue to duo with, you'll be basking in sugary globs of xp.
Melees are soloable, Although you have to buy medkits. they look like they only have one charge on a merchant, but actually have 20. All classes can bind wounds to 70%, and 100% with First Aid3. (total cost 3aas)