I don't know about "Weak". When the event hit my game, they came at me with ships that had guns +1000. Needless to say, every encounter that I had took out my fleet in one round. OTOH, their ships died pretty easily. I usually killed them off losing only one or two fleets. And when they invaded, they used 10 troops.

They also "Appeared" in the system next to my home planet and were in jumping off distance of all of my planets. They were a major pain in my production until I finally dusted them. When they invaded, they didn't always take out the planet, but they did massacre far too many of my people. And took out most of my best ships taking them down.

On the whole, although the actual tactics they used were pretty weak, it was a major thorn in my side for about 30-40 turns. And totally turned the tide on me in the game where I was finally getting ahead.

when i see them i make mass transports and distroy them befor they can make a ship.