Actually, depending on what you want the structure of your tribe to be like, it can be very benefical to sort out your tribe name, tag and members before the world even begins.
Take W4's OA for example. Do you think Vpar2 just woke up that day, started his W4 account, then suddenly got a brainwave for his elite tribe and set it up? No. It was all carefully planned beforehand so that they could get a smooth start when the world began.
The only reason I can see that planning might not be benefical would be if you wanted all your tribe within one K. Whilst you might have a few friends in the K, it results in being better for you to just invite within the area to make for a very localised tribe.
I hope I've put my point across to you well enough.