A few being 6? Because even 6 will not stop a determined force of 12-15 Siege Frigates. I happen to think that the siege ship isn't a big problem, proper scouting helps enormously... but turrets will not actually deter such fleets until they reach 10-20 area... even then you can easily kill the planet, you will just lose allot of ships doing so.
Everyone is listing huge changes and additions instead of realizing the simplest fix..
Just reduce their healthpoints...
Make them as vounerable as scouts, so you NEED normal ships to escort them.
90% of posts have stated that they should have their health points reduced... also 70% of posts have been by people who bought or recieved the game... Yesterday. Give it a week or so.
The overall viabillity of the Siege Frigate will become nill if you have the HP reduced to scout level, it will require tons of baby sitting, as a small group of 6 LRMs could jump in and destroy a large fleet of these expensive mop-up only tools.
It is more exciting and dynamic to have them be more than a mop-up tool. They will be less survivable as a spam fleet if made slower, but exactly as lethal in a proper mixed fleet. That should be the goal, to reduce the effectiveness of a spam fleet, but maintain a battle-capable ship (with escort)... not to reduce the Siege Frigate to the flying, nuking, paper machette ship.