That IS a sort of tactic. It's not the best, but it is a tactic. I haven't beaten that level yet, but there's quite a few people on here that have. And I think you're apporaching this wrong, you're just complaining about how the game is too hard, without asking for help. If you asked people for help, they would give you advice. But, because you're just whining about the difficulty, people get annoyed with you.
If I knew how to beat that one, I'd say it.
Also, here's how to beat "sinking the bis'mar":
Deploy everything, order the two closest points to be captured, and rally the carrier group south of the middle point. When the enemy drones appear, give harass orders on them. Manually capture the last point, and stay back a little, so the enemy capital expends all their missiles. When all enemy drones are dead, order your drones and carrier to retreat, so they don't get destroyed (optional). Then, just let your two last ships fire at it, while you fly behind it, firing antimatter at it's engines, and then fleeing to a safe distance. Make sure that your shields are up while you're being shot at, and remember to vent flux as soon as you're out of range from his guns so you can get back in there.
That's how I did it, and I got 100% completion that way.