There have been some fan made subs on the previous games, so maybe if we assemble a team, we could do it. Have a Red Point for the wiki effort.
What you say is similar with the STS (Steam Translation Server), where all the fans who love Steam translate it and Valve's games. There's also an official Greek STS group there, resulting the official Greek languaged Steam and some games (Half Life 1, as example). I have translated 95% of the HL2 episodes all alone, while the rest of the peeps were focused with CS: GO. We can do it.
For that to happen, we'll need the whole TW game's texts before we translate it and check for grammar mistakes before have it officially done. After we do the final check, we can send it back to the CDP guys to implement it.
In Steam, they used such method in their site, which translates each dialogue/thought per time.
For that part, we need a selected group of jobs:
Translators: Those who have lower and above level of English knowledge to translate it into Greek.
Authors: Those with the Greek Philosophy knowledge to help us out with the checkings. I can help out, because I'm going to a school for beginner authors to expand my knowledge before completing my own books in Greek language.
Admininstrative Author: This one is a special case, because he does the final check before sending it back to the devs to implement it.