You got a decent size force Indeed.
Might its 4. 2 the king, 2 the taskmaster, 0 the wraith cause you didnt payed.
You got:

Decent sized cav group
A nasty melee king
A bit more tactical taskmaster to let you pull some tricks...
Wondering why the black numenorians though (harad/umbar themed?) It does seem decent.. .numbers aren´t far to off what you expect from harad at 500pts

Maybe you could drop a few spears to get a might point on the wraith or even a fate point (which seems more vital) a wraith with no fate its a potencial legolas burn out might shoot to remove the caster in a go... with a fate point in it, you just avoid nasty stuff or least get a good gamble chance to see if the openent wanna risk or not.

Why removing the spears? cause I do honestly dont see much spear support fighting here really... a good portion of the army its cav (which with warspear its a spear as well), then another portion its more elite units in which haradrim are kinda cannon fodder, it may work, but I think those guys might be better applied as cannon fodder blockers to let your key units do their work...

Yeah the Black numenoreans were just Harad stuff that could be led by a generic wraith. I liked the idea of spears behind the elites and then I had extras ready to get behind the Black numenoreans but that makes sense, buff up the wraith a bit. I haven't gotten to play it yet but I am pretty excited to give it a go. I would like to get another might in there probably on the wraith. 5 feels a lot better then 4 even with the task master. Having the cav makes controlling priority and what not.

Edit: I think I am gonna take 5 spears out, although I dunno how I'll model that :/ and give the Wraith an extra 1/1/1

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Cheers,

P

Can you post some pictures of the army?