There are two easy, one fairly easy, and one not so easy points nearby.
I think the patch that went from 1.50 to 1.51 is what did it. On the DoW boards back then, folk were saying "no problem" with Orks in Mission 4. But 1.51 came after those threads and I saw a few "what-the-hell?!" posts after that.
With 1.51, the Orks start with 30 or so resource points and maybe 10 energy points, with no already captured points and one small generator. You do not start with even enough to put bomb chukkas on the two wartrucks you start with. Not even enough points to build one single builder unit. Not enough points to start researching anything.
When you do capture the two close points, you do not have a builder unit to put on listening posts to increase resource rates. If you wait and do build one, now you don't have enough points to build even one listening post. Even if you don't build pistening posts, you still don't have enough to build even one more generator for quite a while.
Meanwhile, the land raider is on its way to the shield opening and the Eldar are moving their base further away and building up forces.
Maybe there is enough time to huddle down and try to build a mek and try the teleport trick. I wonder, though.