Thank you for pointing out the Smite Mastery i thought i put one into it but i mistakenly put it into savvy instead. Alright i will switch lethality with sunder thanks for the tip

3v3 style. Something you won't see from me :) Good to have an option here :P

Runes:
I HIGHLY suggest taking ArP Marks. 15% AS is way lower in dps terms than ArP. Early game you will have your HC anyway for that AS boost. ArP while it lowers the use of your passive, will let you kill creeps/champions faster. Also AS does nothing for ultimate, while ArP benefits from it greatly.

Abotu Wit's end, i suggest adding a Last Whisper as an option when you face "ninja teams" like you wrote :P

Summoner spells.
Imho Flash is the master of 3v3 map. There are so many places you can use it, while Ghost is fairly wasted due to the size of the map.
But guess this is more of a player preference, it might be added in guide.

Masteries.
Ok a 1 big mistake imho. Instead of taking 3/3 Lethality i HIGHLY suggest taking 3/3 Sunder.
Your build has nothing to do with Crit itself <10% making Lethality a rather waste points.
Also instead of 1 point in Archmage Savy i suggest taking 1/1 in Smite mastery for bonus gold. Imho way better investment than 0.2AP/lvl.

Desc looks ok, i will not comment on it since i dont play 3v3 (personaly i hate this map) so cant even tell if the jungling is ok or anythin.

Good to have a jungling WW guide for 3v3 players tho, imho it requires some rethinking but still decent job.

I hope my Guide is helpful to those who are new to Warwick