I'm going to be brutal here. Wyches are okay in very small units because they can act as stumbling blocks for a reasonable price and blockades to assault units. I do not find a lot of value in them otherwise.
At 1K I would consider them to be a bit stronger. Long term the expenditure wont be worthwhile though.
The Succubus with Archite Glave packs a lot of punch but that has nothing to wo with Wych's directly.
At 1K the rest of the army can hide the deficiencies of the Wych's by using Disintegrator Cannons on the enemy to soften them to the point that 5 Wych's can be quite effective at tying them up or even winning. Certainly good enough to at least die on the right phase (the enemies assault phase) leaving thm open to more Disintegrator fire.
Venoms are another option. I happen to like the 3 HP on Raiders more, but the 12 shots off of a Venom with poinson averages 4 wounds before saves. The disintegrator only averages 1-2 so one can debate the merits back and forth depending on how much cover is typical on your boards.
the safest bet is Venoms though so taking a Court of the Archon heavy with Sslyth to lead th army and then taking Wychs in Venoms with Dual Cannons and a succubus with glaive seems like a really strong way to go if you're set on Wych's.
Hold out bait to entice the enemy. Feign disorder, and then crush him.
-Sun Tzu, the Art of War