See my answer @ Best strategy against Worker Rush cheese in 2v2 and other matchups
In response to the specific answers in this duplicate question though...
All workers move the same speed, and none are ranged. This gives you the option of just running around, not letting the enemy do much harm, while your ally builds an army as quickly as possible with his untouched base. At that point it's basically a 1v0 game until your opponents can resurrect their economy. Personally I think that worker micro is too risky in this situation for the following reasons:
- Running is easier than attacking. When you attack with workers, no matter how good you are, sometimes it just ends up in the opponents' favor if they micro better than you or if you find yourself in a bad position or panic.
- You will have a slight advantage because of worker count, but you can increase your advantage the longer you delay their attack. They will have no reinforcements coming. If you attack right away they will have 0 workers to your 2. If you wait a while, they will have 0 workers to your 2 workers and 4 marines.
On the devils' advocate side though, there are probably ways of combining this attack with a 6-pool or proxy rax which could make things much trickier to defend against.