By following basic logic, the Lucian Alliance shouldn't be a threat to Earth, and that applies to their SG-1 appearances as well. The Lucian Alliance rely on Goa'uld Ha'taks, which we've seen on SG-1 can be destroyed in two shots by a puddle jumper. Earth has a fleet of BC-304s outfitted with advanced Asgard weaponry which can successfully take on an Ori warship. There is no way a Ha'tak should be able to stand up to a 304.
The whole "cloaked cargo ships are undetectable" is pure bullshit. Cloaked cargo ships were regularly detected in SG-1, Earth with Ancient and Asgard tech should have no problem doing the same.
But I guess this was just conveniently ignored for the sake of "creating drama."