The problem seems to be that inside and outside of battle, they aren't that effective. A good example was when they where infront of a thievesguild hideout, with one barbarian and two rogues at guard. They took hours to figure out what they would do...
What were the thieves (from the guild) doing all this time the PCs were lurking outside having a big argument about how to attack their lair?
In battle, its much more like there is a fighter fighting over there, a ranger over there and a sorcerer at the other side of the room.
Have your monsters divide and conquer. If the party fights as three independent units, have the minions pin down the Fighter and the Ranger, while the BBEG makes a beeline for the Sorcerer. (But have the NPCs take them prisoner, unless you want a TPK.)
After the first few times the party have their asses handed to them, they'll start to get the message.
Is this sounding familiar? Anyway to get to smooth things down?
Yes. And your players will adapt their play to the style that your game rewards. So, if you want quick, decisive action, you have to reward quick decisive action and 'punish' indecisive action and dithering.
So, if the PCs take hours deciding how to deal with the thieves, have the thieves reinforce, or counter-ambush the PCs, or something similar.
In combat, ask the player what they want to do... and if they don't start declaring their first action within 15 seconds, they lose their turn.
When PCs
do act decisively, even if their tactics are therefore sub-par, don't punish that. Consider having your bad guys be demoralised by a sudden rush (either a -1 morale penalty on attacks, or just have them break and run/surrender).
And so on. Reward the play you want to see, discourage the play you don't want to see, and your problems should sort themselves out.