Yeah, stick with it.
Here is one strategy:
You can try to work your way up and right. I've found a little less resistance there at the beginning. Then circle the big asteroid which is close by. This will allow you to build some force. Try to avoid challenging or even defending against the Greys early on. They are strong and fierce and will send many seedlings even to a small roid to defend against you. Also avoid the space directly between the two large roids. You'll know what space I mean once you've spread a bit. This is where the Greys travel most and they like to conquer those roids. Hopefully with about ten roids won you will have some momentum and can decide
where to go next.
Good luck and happy planting.