My party fluctuates between four and ten people. Needless to say they steemroller a lot of stuff especially since I use slower dying and a simple wound rule. So they are very capable of taking out a lot of stuff without thinking.
Anyways, a party with hirelings and cohorts is pretty powerful. What I have discovered is that with my weird rules, a good fight is one that is made up of equivalent numbers of the same level. That is 4 level 3 PCs can take 4 CR 3 monsters. A group of four characters is supposed to have a decent fight with one creature who's CR is equivalent to the average party level. If there are twice as many in the party (including cohorts and hirelings) then you can take 2 creatures of eqivalent CR to APL. If you are using a rule tha tmakes it harder to die consider it to be another 4 people and assume that they can now take 3 monsters with CRs = APL. With two rules that make it harder to die add another 4, and another monster.
So last time I had a party of 4 3rd level PCs. Normally they would have a hard time with one Dread warroir. However we use 2 rules that make it harder to die quickly. (its the slow deaths you have to watch out for in my campaign) So that makes the party essentially a 12 person party of APL 3. that means I have 3 dread warriors, I want to make it a little tougher so I make it four dread warriors. There were only 2 party members left standing at the end of the fight and one was about to go down. It was rated as the best fight so far!
Aaron.