Here's a piece of advice that I found works very good while playing skirmish mode. Most people when they play EaW space skirmish use one of two tactics: (2v2)
1. One person beats through upgrades and the other fights the enemies/captures mines.
2. Upgrades are done sporadically by random people.

I found it's much easier if instead of one person doing upgrades, you both do it. Instead, you alternate who is upgrading so that you both utilize your gathered resources and can still use the ship limit of two players (this is why you don't just give your funds to the other guy.) I used it and it helped to pretty much obliterate 2 opponents, especially after one jumped us with about 5 acclamator cruisers at our base.